Help-Installing XM Radio

I just purchased my first BMW, a 325xi wagon(and am never looking back!) but I want to install a XM radio. Since I am stubborn, I want to install it myself. Any suggestions on a)getting the antenna through the firewall and into the cab and b) hooking it up to the existing sound system? Lemme know what you think! If nothing else, I will give in and take it to a pro! Thanks

I ended up installing XM Snap. Inexpensive. Portable. Installation took 15 minutes (time to route antenna wire). Perfect.

No need to make a hole in the firewall. XM antenna leads are designed to be flexible and thin enough to tuck under weatherstripping. Having said that, have you considered Internet radio? Cheaper than satellite, with equal or better variety and reception and no real installation needed.

Which XM unit are you installing? I have the BMW Sirius unit in my car, but use the Starmate Replay (old school portable) in my Jeep. I found the FM modulator to be invaluable for making a clean connection to the stock sound system. It connects between your FM antenna and the "radio" which for the BMW is in the trunk. An adapter will be needed, so you'll need to source that somewhere - not sure where to get this.

I have my antenna under the rear deck as many do and the reception is decent. I don't want it externally visible and the drag it produces slows me down for autocross.