BMW 420i (F32/F33/F36) (13-20) Quad Exit M4 Style Performance Exhaust Conversion

Transform your BMW 4 Series 420i with a premium quad-tailpipe rear section and matching M4-look lower valance. Hand-built in the UK from T304 stainless steel, this axle-back conversion delivers a sharper, deeper tone and a more purposeful aesthetic to match the car’s performance character.

We’ve installed this setup on customer cars and in-house builds, and the feedback has been outstanding. The fit, finish and road presence are superb, with aggressive slash-cut quad tips filling the new diffuser perfectly. If you want that motorsport-inspired look and a richer soundtrack without compromising everyday usability, this is the upgrade to choose.

Why choose this quad-tip system

• M4-style visual upgrade with included quad-exit lower rear panel - designed to suit the M Sport bumper
• Replaces the factory rear section from the centre joint back for a clean, OE-style installation
• Precision TIG-welded T304 stainless steel throughout for durability and long-term corrosion resistance
• 2.5 inch 63.5 mm mandrel-bent pipework for smooth flow
• Slash-cut quad tailpipes for a bold, factory-plus finish
• Made in Sheffield, UK

Vehicle compatibility

Suitable for BMW 4 Series 420i petrol with M Sport rear bumper:

• F32 Coupe, F33 Convertible, F36 Gran Coupe - including LCI facelift
• 2013 to 2020, B48 turbo petrol models
• Compatible with factory-fit tow bar

Manufacturer offers versions for both N20 and B48 420i engines. This listing is for non-OPF non-GPF fitment. Please check your car’s setup before ordering.

OPF GPF PPF fitment guidance

• UK Europe 2013 to 2017 - typically pre-GPF
• Rest of World 2015 to 2020 - varies by market
• UK Europe 2018 to 2020 - many cars have GPF OPF PPF

Not suitable for vehicles equipped with a GPF OPF PPF. The pre-PPF and Rest of World variants will not fit GPF-equipped cars.

What’s included

• Centre to rear section quad-exit exhaust system
• M4-style quad-exit lower rear valance diffuser panel
• All required clamps, fittings and gaskets

Installation notes

• Cutting of the original exhaust pipework is required at the centre joint
• Direct replacement from the centre back - designed to integrate cleanly with the supplied rear panel
• Professional fitting recommended

Prefer a hassle-free install Our workshop can help. Book fitting with MJ Modifications in Warwickshire - request a quote at info@mjmodifications.co.uk.

Built for enthusiasts

This quad conversion is a perfect match for tuned and remapped 420i cars looking for a stronger note and head-turning style. Expect a sportier soundtrack and a far more assertive rear profile that looks right at home on the F3x platform.

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