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
Give your BMW M140i (F20/F21 LCI, OPF/GPF equipped) a significant exhaust upgrade with this Milltek Sport Resonated OPF-Back Exhaust System. Specifically engineered for OPF/GPF-equipped LCI models, this system replaces the cat-back section from the OPF outlet rearwards, delivering noticeably improved exhaust character whilst retaining the factory particulate filter.
The resonated design smooths out drone and harshness for a pleasant road-going experience. You'll immediately notice a richer, more refined exhaust tone — particularly at higher revs — making this system well-suited to daily drivers who want an improved sound without excessive volume. Available in five tip finishes. No remap required.
Fitment: BMW M140i F20 & F21 LCI (OPF/GPF equipped models)
E-marked: EC approved
Tip options: Polished, Cerakote Black, Titanium, Burnt Titanium, Carbon Fibre
