At a little more than half an inch thick, the Delphi Roady XT is an incredibly compact XM satellite radio. Width and height aren't bad either, coming in at 3.7 and 2.2 inches, respectively, making it the smallest satellite radio around. It includes a car mount and interfaces with a car stereo via a built-in FM transmitter. The unit also includes a line-out for a more direct connection to a car stereo through an auxiliary input or a cassette adapter. Powered by a rechargeable battery, the Roady XT also takes an optional 12-volt adapter available from Delphi.