Any body install one of those XM modules in 03 Deville< easy? works ok?

[Sgt Grits]

I have a Basic single cd, cassette am/fm sound system. I want to ad my XM radio to it. There is a 65$ module that is supposed to hook up easy and use existing display for xm also. Has anyone installed this. Keeping Caddy completely stock looking. But will ad an xm radio if I have to. Thanks Sarge