3DDesign Side Skirts, Side Skirt/Rocker Sill Extensions for BMW 4 Series (G22 G23) 2020+ Coupe & Convertible | M Sport & M440i | Urethane Aero Side Blades Splitters | OEM+ Body Kit Styling

Transform the profile of your G22 or G23 with 3DDesign rocker extensions

Give your coupé or convertible a sharper, lower, more purposeful stance with these premium 3DDesign sill extensions. Engineered for precise alignment with the factory M Sport side mouldings, this exterior upgrade delivers a clean OEM-plus look with true tuner pedigree. The high-grade urethane construction offers excellent durability for daily driving while maintaining a refined finish that elevates your car’s presence.

Why enthusiasts choose this upgrade

• Clean OEM-plus styling that visually lowers the car and enhances the side profile
• Precision moulded urethane for robust impact resistance and long-term durability
• Designed specifically for M Sport package cars and M440i for factory-level fit
• Supplied with fixings for a straightforward install using the original sill area
• Perfect foundation for a cohesive aero package alongside front and rear styling

Finish note: Supplied unpainted and ready for preparation. We can arrange colour coding to match your bodywork or a contrasting finish to suit your build.

Professional fitting and paint

Want it fitted perfectly first time? Book expert installation and paint with MJ Modifications in Warwickshire. Email info@mjmodifications.co.uk for a tailored quote.

What you receive

• Pair of 3DDesign urethane rocker extensions left and right
• Installation hardware

Vehicle compatibility

• G22 4 Series M Sport 2020+
• G23 4 Series M Sport 2020+ cabriolet
• G22 G23 M440i 2020+

Search-friendly terms to help you find the right part

BMW G22 side skirt extensions, BMW G23 side splitters, rocker extensions, sill extensions, side blades, ground effects, aero side skirts, body kit side pieces, M440i side trims, M Sport rocker panels, exterior styling upgrades, performance styling for BMW coupé and convertible.

We have fitted these for customers and the feedback has been consistently positive on both the fitment and the finish. For advice on paint options, installation, or lead times, contact the team at info@mjmodifications.co.uk.