The ULTIMATE guide to modifying your G8X M3 or M4

The ULTIMATE guide to modifying your G8X M3 or M4

We love anything G8X here at R44. Our passion for the platform is always growing and we're committed to helping you achieve your ultimate G8X build! This is our in-depth, fully comprehensive, guide.

Despite the initial controversy, the G8X platform is not at all bad looking - it’s a great foundation that can be easily enhanced to your specific individual preferences. 

So how do I achieve the perfect look for my G8X?

Exterior Styling

The majority of parts mentioned are suitable for both the M3 and M4, with the only exception being the rear spoilers and side badges. All carbon upgrades are pre-preg for additional strength, reduced weight and outstanding quality because: why settle for less?

Let's start with the front. The first thing that stands out is the enormous, newly redesigned, kidney grilles that shook the internet back when the car was first unveiled. To enhance these grilles, your primary options are a set of classic GT-style grilles or the more aggressive CSL-style grilles from MHC+ - both of which are crafted from state-of-the-art pre-preg carbon fibre with a high gloss finish.

Also crucial, is the addition of a high-quality front splitter to give the car a more aggressive and imposing look. Our most popular front splitter is the infamous SP1, which extends outwards considerably for maximum aggression. The SP1 project was taken from start to finish here in the UK, from design conceptions to distribution. The product utilises the latest carbon composite manufacturing technology to provide a product that is both cost-effective and environmentally friendly.

For a more classic look, we also offer the ‘performance-style’ front splitter, taking design inspiration from BMW’s M Performance styling range. Again, both options are finished in pre-preg carbon, so the decision is really down to your personal taste. More affordably, we also now offer the performance-style front splitter in gloss black.

To finish things off, you could also consider a set of carbon ducts. We offer a classic single-fin solution as well as our popular twin-fins for owners looking for the most aggressive option. We find the ducts tie the other carbon front-end upgrades together, creating one beautiful and cohesive look. More affordably, the single fin performance-style ducts are available in gloss black.

Moving on to the side of the vehicle, a solid side skirt is essential to continue the low line set out by the front splitter, providing a lower and wider look. If you chose to go with the SP1 front splitter we’d highly recommend selecting the SK1 carbon side skirts for a cohesive design language - likewise, if you opt for the performance-style front splitter, we recommend also going with the performance style side-skirts. However, feel free to mix and match. Key differences include a fin design on the performance-style, whilst the SK1 has a wider flat design.

We also offer an OEM-style side skirt which mirrors the design of the performance-style skirt - without the aggressive fin for a more sleek and subtle look.

To complement these carbon fibre additions, we’d recommend upgrading your vehicle’s side badges to an MHC+ carbon fibre replacement. More affordably, we also offer a carbon side badge trim that adheres to the standard gloss black item. When enhancing any vehicle’s exterior, the small details are so important and are often the most cost-effective areas to upgrade.

Now for the rear… The factory rear spoiler is subtle and not to everyone’s taste. We offer a wide range of rear spoiler upgrades, with a style to suit everyone's personal preference.

If you're a fan of the OEM spoiler, but want a more premium, high-quality, item, the MHC+ OEM-style spoiler in pre-preg carbon fibre is the perfect solution.

If you're at the other end of the spectrum, looking for something a bit more crazy and unique, the MHC+ rear wing may be the answer!

Pair your favourite spoiler with either the OEM-style rear diffuser or performance-style rear diffuser to complete your G8X’s rear end.

The MHC+ OEM-style rear diffuser is a 1:1 copy of the factory rear diffuser, however, the MHC+ item offers far superior quality in the pre-preg carbon fibre as well as a weight saving over standard.

Our popular MHC+ performance-style rear diffuser shares many similarities, however, the fins are deeper with the outer set at an angle for a slightly more aggressive look.


Unfortunately, the factory wheels don’t sit flush with the wheel arches. Luckily for you, we’ve had plenty of time to play around with different spacer sizes and combinations, as well as hundreds of installations, to determine what we think is the best spacer setup for the platform. We recommend 12mm front and 15mm rear, with a 66.6 centre-bore and a 5x112 pitch circle diameter (PDC). The brand we always use is Bimecc as they are machined from high-quality aluminium, zinc coated for corrosion resistance and TUV-approved.

It's important to note, you will need to mould the arches to prevent tyre rubbing. Our detailed YouTube install guide walks you through the full process. 


The G8X’s standard dampers are very capable, however changing the suspension setup allows you to:

  • Achieve your perfect stance
  • Improve handling
  • Have greater adjustability

The most cost-effective option is the Eibach Pro-Kit front lowering springs (E10-20-049-01-20 - available at R44 Performance). Changing just the front springs has the benefits of sharper turn-in, more feedback through the steering wheel and reduced body-roll when cornering. The arch gap is also much more prominent at the front axle, so a set of 20mm front lowering springs really does go a long way, visually. 

For a full set of lowering springs, we recommend these items from H&R (28616-1 - available at R44 Performance). Lowering 30mm at the front and 10mm at the rear, opting for a full set reduces squat under acceleration and dive under braking, allowing your vehicle to remain balanced whilst on the limit. 

If you’d like the convenience and affordability of lowering springs, but the adjustability of coilovers, adjustable ride management systems from the likes of MSS and KW may be the perfect option for you.

As they are fundamentally lowering springs, you will retain the functionality of the factory electronic damper control (EDC) - something you’d have to sacrifice with a full set of coilovers.

We have the MSS sports adjustable extra low ride management system (02bBMWMG8x - available at R44 Performance) fitted to our development G80 M3 and are so pleased with the results.

To achieve maximum adjustability, especially for the track, the ultimate suspension upgrade is the V4 3-way adjustable coilover kit (3A7200EB - available at R44 Performance) from KW. With this option, you can adjust the rebound as well as both low and high speed compression damping. This allows you to tailor your suspension setup to your specific preferences, driving style and environment.


From the factory, the G8X platform is certainly no slouch when it comes to performance. However, this is R44, and we know a thing or two about how to get the most out of your M3 or M4. As the G8X platform utilises the fantastic S58 twin-turbocharged engine, airflow and cooling are essential to see substantial power gains. 

An uprated intake system is a great place to start your tuning journey. The aim of upgrading your intake is to increase airflow, reduce inlet temperatures and add some awesome intake noise! 

Most affordable, is an open filter system from MST (MST-BW-S5801 - available at R44 Performance). It features laser-cut heat shields to prevent any heat soaking of the cone filters, keeping air temperatures cooler and making quite a cool sound.

The next step up are full carbon fibre cold air intake systems from Armaspeed and Eventuri. The Armaspeed item has great results - we have an Armaspeed intake (ARMABG82M4-A-3/4) fitted to our G80 M3 which has taken on long roadtrips, as well as trackdays, keeping intake temperatures consistently cool. Alternatively, the Eventuri system (EVE-G8XM-CF-INT - available at R44 Performance) features patented Venturi housings for maximum air volume and intricate air flow technology for the most substantial results. 

In terms of exhaust systems, we will always recommend our incredible R44 full titanium cat-back system.

The lightweight titanium construction offers an enormous weight saving of 16kg or 35-lbs. The system removes the secondary catalytic converters, OPF filters on EU cars, the large single resonator for a less restrictive double resonator setup, as well as a redesigned rear silencer for optimal airflow when the valves are open. Back-pressure is dramatically reduced, resulting in faster throttle response, greater tuning potential and a vastly improved exhaust note. For a full breakdown of the system click here.

If you do not wish to opt for our titanium system, there are stainless steel options available from Remus and Milltek. These systems are slightly more affordable, also unlocking greater tuning potential as well as improving sound - however the weight saving isn’t quite as significant.

R44 also offer both catless and 300 cell catted downpipes to further improve airflow and achieve the best possible results.

In regards to tuning, there are now a number of vendors competent in tuning the G8X platform. Alternatively, if you’re looking for a convenient, untraceable tuning option that can be easily removed, we’d recommend going with a tuning box from the likes of RaceChip, daHler and Burger Motorsports

We have utilised the RaceChip GTS black tuning module on our development G80, adding a staggering 140bhp and 110Nm of torque! As an alternative, the JB4 from Burger Motorsports offers a range of customisable features with smartphone integration, as does the tuning module from daHler.


With all this added performance, you’re going to need some stopping power. We’ve worked closely with EBC to develop some incredible 2-piece floating, drilled, grooved & vented brake discs, which we then paired with EBC’s yellow stuff pads. We find this to be the ultimate setup, however, feel free to experiment with different disc and pad configurations. 


Now that you’ve built a truly special machine, it’s crucial that it feels just as special from inside the cabin. We have some SHFT carbon fibre trim upgrades as well as replacement buttons. However, by far the most premium upgrade is the installation of a beautiful bespoke SHFT steering wheel.

There are a range of options to suit your specific requirements. Both flat-botton and rounded variants are available with a choice of materials including carbon fibre, perforated leather, smooth leather and alcantara, as well as bespoke stitching and 12 o’clock marker. SHFT even offer a race LED display with shift lights for those who want to be the most bold. If you want something completely bespoke, please get in touch to see what we can do for you!


If you’re still looking for even more bespoke customisation, IND offer colour-matched reflector deletes as well as painted or carbon fibre roundels. They even offer fully bespoke engine covers to make your G8X a true 1-of-1!

So there you go! Everything you need to create your dream G8X. If you'd like to turn that dream into reality, don't hesitate to get in touch! Shop the full G80 collection here & view the G82/G83 collection here.

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