This 2000 Audi S4 has been extensively modified into a high-performance build that blends OEM+ RS components with modern upgrades and motorsport-grade hardware. Finished in Panther Black over a black leather interior, the car is powered by a twin-turbocharged 2.7-liter V6 that has been fitted with TTE550 turbochargers, Wagner intercoolers, upgraded intake and exhaust systems, larger injectors, methanol injection, and MRC software. Supporting modifications include a Bosch 044 fuel pump, APR bi-pipe, front-mounted oil cooler, and B5 RS4 clutch and flywheel. While the car runs, the seller notes that the current tune requires work from a specialist to fully optimize the setup.
The exterior features an RS4 conversion including front and rear fenders, doors, and front bumper, along with an S4 rear bumper modified with RS4 lower trim. A US-market S4 trunk lid, Maxton front splitter skinned in carbon fiber, and Opel GTE-style carbon hood gills further distinguish the build. The Panther Black paintwork benefits from an eight-year ceramic coating, and while minor age-related blemishes are present, the finish overall is described as excellent. The car sits on OZ Racing Superturismo Dakar wheels measuring 20x10 ET26, fitted with an MG-Line center cap kit.

Underneath, the suspension has been upgraded with Airlift Performance air suspension with 3P management and a seamless airtank finished in carbon fiber. Additional handling improvements include H&R anti-roll bars, 034 Motorsport billet aluminum subframe reinforcement, and B5 RS4 upper control arms. Braking is handled by a set of R8 380mm ceramic front brakes and RS6 356mm ceramic rears with Lamborghini-sourced handbrake calipers.

Inside, the cabin has been fitted with Recaro RS3 Wingback seats, an RS4 cluster with multi-function display, RS4 carbon trim, an Audi TTRS flat-bottom steering wheel, and an AEM boost gauge with methanol controller. A7 rear seating and a 2015 A4 rearview mirror with updated sunroof controls modernize the interior further, while factory black leather trim remains present.