The 2004 Cadillac XLR ($75,385) comes one way, with a convertible hard top. Its 4.6-liter V8 engine is mated to Cadillac's newest five-speed automatic transmission.XM Satellite Radio is the only option ($325). The list of standard equipment is long: side-impact airbags, a nine-speaker Bose sound system, DVD navigation and video, StabiliTrak electronic stability control, radar-controlled adaptive cruise control, keyless entry and push-button start, a head-up display, and OnStar, the highway assistance service featuring the helpful voices of genuine human beings beamed to the car by satellite. Next Page