Did f-bodies ever have factory XM Radio? Or were they discontinued before GM offered this? And if they did have factory XM, is there anyway to put a factroy headunit with XM in my 99 formula?

 

No, satellite radio was never offered as an option on f-bodies. This is despite the fact that it was being offered on other GM models while the f-body was still in production. The same thing goes for OnStar - available on other GM models but never on the f-body.