String Theory Garage will be closed to the public from Wednesday, 29th July to Thursday, 6th August for our annual shutdown.
If you need to get in touch, please leave us a voicemail or send an email. Our team will happily get back to you when we return on Friday, 7th August.
Shopping online? Don't worry! Our online store will remain active! We hope to ship orders placed for in-stock items as normal during the shutdown. Anything else will be dealt with upon our return.
Thank you for your understanding, String Theory Garage Team
For the full-on exhaust experience on your BMW M135i (F20/F21), the Milltek Sport Race Rear Silencer delivers maximum sound impact. This non-EC-approved race silencer is designed for performance driving and track use, producing a more uninhibited, aggressive exhaust note than the road variant — best suited to track days or spirited road use where volume is welcomed.
A direct bolt-on replacement for the OEM rear box, the race rear silencer works with your existing front exhaust sections and catalysts. Manufactured from 304L stainless steel in the UK, it is available in three tip finishes including the premium titanium option.
Fitment: BMW M135i F20 & F21 (Non xDrive models)
Race product: Yes
Tip options: Polished (SSXBM959), Cerakote Black (SSXBM960), Titanium (SSXBM1026)
