Milltek Sport Cat-Back Exhaust for BMW 4 Series F32 428i Coupe N20 (2014-2020) 435i-Style Dual-Outlet, Non-Resonated, Polished Tips Requires 435i M Sport Rear Valance Automatic, No Tow Bar SSXBM1013

SSXBM1013 Milltek catback for BMW F32 428i 2.0T Coupe, twin exit 435i look, loud version with mirror polished tailpipes

Part number: SSXBM1013

Give your BMW 4 Series 428i the soundtrack and styling it deserves. This UK‑engineered Milltek catback transforms the rear of the F32 2.0 turbo petrol with a proper 435i‑style twin exit and a sharper, more purposeful tone. The resonator‑delete configuration delivers a noticeably louder note under throttle while remaining civil on a steady cruise. If you want a premium stainless steel system with a factory‑plus aesthetic and a freer breathing layout, this is the upgrade that completes the car.

Built from T304 grade non‑magnetic stainless throughout, the system uses smooth, mandrel‑formed bends and an optimised pipe diameter for improved flow and response. The mirror polished tailpipe trims sit perfectly under the 435i M Sport diffuser for that OEM twin finish without looking aftermarket. Designed, developed and hand finished in Britain, it offers long‑term durability, excellent fitment and a refined, sporty soundtrack with minimal cabin boom.

Why enthusiasts choose this Milltek system

• Twin exit 435i look for a clean factory‑style dual tailpipe conversion on the F32 428i.
• Louder option thanks to the resonator‑delete layout for a deeper, sportier tone.
• Mirror polished tailpipe trims for a premium rear end finish.
• T304 stainless steel construction for corrosion resistance and longevity.
• Mandrel‑formed pipework with consistent diameter for freer gas flow and crisp throttle response.
• Sound developed to reduce unwanted interior boom for day‑to‑day usability.
• Engineered and hand finished in the UK by Milltek.

Fitment and requirements

• Vehicle: BMW 4 Series F32 428i Coupe, 2.0 turbo petrol, N20 engine code.
• Model years: 2014 to 2020.
• Transmission: Automatic models only.
• Tow bar: Not suitable for vehicles with a tow bar.
• Finish: Dual exit with mirror polished tailpipe trims.
• Sound level: Louder, non‑resonated configuration.
• Important: Requires the BMW 435i M Sport rear valance or diffuser to complete the dual exit conversion.
• Milltek part number: SSXBM1013

Real‑world results

We have fitted this setup to our own builds and for multiple customers. Feedback is consistently positive on the fit, finish and the more engaging tone. The twin exit look completely lifts the rear of the F32 while maintaining a factory‑clean appearance.

Professional installation

For fitting, book with MJ Modifications in Warwickshire. Request a quote: info@mjmodifications.co.uk.

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