Introduced in 2012 and built exclusively as an Avant, the B8 RS4 was the last of its line powered by Audi's high-revving 4.2-litre naturally aspirated V8. Developing 450 PS through a seven-speed S tronic gearbox and quattro all-wheel drive with a sports rear differential, it paired supercar pace with five-seat, estate-car practicality, a combination that has made it one of the most sought-after fast Audis of the modern era. This particular car is the rare 'Limited Edition', the run-out specification offered at the very end of B8 production and a markedly more expensive proposition than the standard car when new. Where the regular RS4 listed at 56,545 GBP, the Limited Edition commanded 65,545 GBP, and for that it gathered nearly every desirable factory option into a single specification: 20-inch matt black 5-arm Rotor wheels with diamond-cut rims, red brake callipers, Sports suspension plus with Dynamic Ride Control, dynamic steering, the raised 174mph speed limiter, sports exhaust, the carbon engine-bay package, matt aluminium styling, privacy glass and a Bang & Olufsen sound system. It is the interior that sets the 'Limited Edition' apart. In place of the standard seats, it received the Audi exclusive contrast package: RS4 bucket seats trimmed in quilted Valcona leather with a diamond design, finished in black with Audi Exclusive Crimson Red, RS embossing to the front backrests, and a matching Audi exclusive controls package and floor mats. Finished in Panther Black, this example was delivered new through Audi Slough on 15th May 2015. The original owner specified it further still, adding the Open Sky panoramic sunroof, Aluminium Race inlays, heated rear seats, Audi side assist, high-beam assist, advanced parking, Audi connect and the debadged rear, with later additions of a Milltek sports exhaust and 10mm wheel spacers. What truly distinguishes this car is how it has been maintained. From its pre-delivery inspection onwards, it has been serviced almost exclusively within the Audi main dealer, building a near-unbroken annual record from 49 miles to its present 94,600. Inspections, oil services, brake fluid changes, spark plugs and gearbox and final-drive oil have all been attended to with a 'money is no object' approach. Now with one previous keeper from new and accompanied by both keys, the service key, tool kit, book pack and a substantial file of documentation, it represents an unusually well-kept example of the last naturally aspirated RS4.