Our Brilliant Red 2007 Audi S4 Cabriolet carried a base price of $56,420 including the $720 destination charge. Add the mandatory gas guzzler tax of $1,700, and the least expensive S4 Cab will run $58,120. Heated front seats tack on another $450, and we’d recommend the optional $1,200 Tiptronic automatic transmission if you plan to do lots of city driving. The premium Bose audio system is an even grand. A Convenience Package is priced right at $1,050 and includes a wind blocker, adaptive front lighting, rain and light sensors, driver’s seat memory, auto-dimming mirrors, and a Homelink transmitter. Our test sample also had Audi Navigation Plus ($1,950) and carbon fiber beltline trim ($400) to bring the total price to $62,970.