Here are some pictures of my XM install. I choose to mount my Pioneer GEX-P10XMT in the truck, right on top of the factory XM module. I also used the factory antenna. I didn't want to tear out the factory XM. When I sell the car, if I want to remove my aftermarket install, the factory works will still be there. Then I will only need to plug it back in.

I removed the factory XM module along with the bracket it mounts to. The factory bracket was perfect for mounting the new Pioneer XM.



I had to relocate the factory XM module up about one inch so the mounting screws for the Pioneer XM unit wouldn't hit. The red arrows were the old mounting holes.



Top view of the new mounts. Sorry for blurr.



Side view of the new mounts.



The Pioneer XM mounted. The mounts supplied were perfect for elevating the unit up off the bracket away from the factory XM module mounting bolts.



Another view. Top side



Notice the highlighted antenna recepticle. It has two keyed tabs. I had to shave one of them off for the stock antenna connector to fit. I had to remove the top shell of the XM unit to access the recepticle better. But it took all of 10 minutes to complete with an x-acto knife.
Before



After. Notice one of the key tabs is still there? It so happens to line up with the factory antenna plug so there was no need to remove it.



The factory connector also had a tab that needed removing.
Before.



After. This tab was for nothing other then a thumb hold.



As you can see, the factory antenna plug fits the Pioneer XM after mods. And the clip that holds it in place is untouched and still functions.



The unit mounted at home. The factory XM still there with the Pioneer riding bareback.