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
Unlock the flat-six potential of your Porsche 718 Cayman GT4 or Boxster GTS (4.0L, Pre-February 2020) with this Milltek Sport OPF-Back Exhaust System. Purpose-designed for the OPF-equipped (pre-facelift) version of the 4.0L naturally aspirated models, this system replaces the OPF-back section with free-flowing 304L stainless steel pipework — delivering a more characterful, louder exhaust note whilst retaining the factory OPF for emissions compliance.
Available in five distinct tip finish options across three finish families. Designed as a bolt-on OEM replacement — no cutting or welding required. Manufactured in the UK by Milltek Sport.
Fitment: Porsche 718 Cayman GT4 & Boxster GTS (4.0L naturally aspirated) Pre Feb 2020
Tip options: Polished (SSXPO150), Cerakote Black (SSXPO155), Titanium (SSXPO167), Burnt Titanium (SSXPO168), Carbon Fibre (SSXPO169)
