I added XM to my 96 Cobra. It was a Delphi Roady XT that had to be plugged into the cigarette lighter. Then it either a) had to be tuned to a vacant FM station or b) played through a cassette adaptor. From that angle the in dash unit is a much cleaner approach. However, there were many many options on antenna install that Ford chose not to explore. Sadly, most of them were probably no more or less expensive than the miniature computer mouse look-alike that they stuck on the middle of the rear deck. My Roady XT came with a magnetic antenna that measured 1-1/4" L X 1" W X 3/4" H. It fit neatly on the black trim piece just forward of the trunk lid on my 96 Cobra Convertible, and you could hardly even notice it. And it actually privided better reception than the pimple on the center of the rear deck.