Welcome to Onyx Performance, your top destination for BMW, Volkswagen, and Audi tuning, and servicing experts. Located in Slough, just west of London, we specialise in advanced remapping services. Our skilled team is dedicated to custom ECU remapping and performance modifications, unlocking the full potential of your vehicle. At Onyx Performance, we boast a state-of-the-art 4WD Dyno, specifically designed to handle vehicles upto 1500hp. Whether you're looking to maximise performance or enhance fuel efficiency, we tailor our services to meet your specific needs. Explore our online shop for a range of tuning packages and more. Elevate your driving experience with Onyx Performance. BMW, Mercedes and VAG Group Remapping Specialists Our services include a wide variety from Performance Tuning to Dyno Runs, Engine & Gearbox Servicing, Premium Tyre Fitting, Diamond Cut Alloy Wheel Refurbishment, Immobilisers & Fleet Trackers. Using some of the most advanced and sophisticated equipment avai