The 2008 Audi RS 4 is a compact ultra-performance car based on the Audi A4, and it's available in sedan and convertible body styles. Standard features include 19-inch wheels with 255/35 high-performance tires, Dynamic Ride Control suspension, xenon headlights, Recaro sport seats with power adjustment (the Cabriolet has less aggressive, non-Recaro seats) and front seat heaters. Silk napa leather upholstery, carbon-fiber cabin trim, dual-zone automatic climate control, a 10-speaker audio system with six-disc CD changer, a sunroof (on the sedan, obviously) and rear park assist are also standard.A premium package is optional on the sedan and includes auto-dimming mirrors, a navigation system, an upgraded Bose audio system with satellite radio, heated rear seats, Homelink, a power rear sunshade and Bluetooth capability. These items are all standard on the limited-production RS 4 Cabriolet. Integration for an iPod is a stand-alone option on the sedan and a no-cost option in place of the standard six-CD changer on the Cabriolet. The Titanium and Audi Exclusive Packages add special exterior and interior trim features to the RS 4 sedan.