Installing a Satellite Radio Antenna
The antenna is a vital element of your satellite radio setup; without it, you can't receive the signal. The best place to mount the antenna is on the roof of your vehicle, as far from obstructions (such as roof racks) as possible. This will ensure the best possible signal reception and reduce instances of signal dropout.
Most new satellite radio antennas feature strong magnetic bases which secure tightly to your vehicle's roof. Some might also incorporate self-adhesive pads, but these are not as easy to remove and are generally not used unless the installation is, without a doubt, permanent.
The biggest challenge is running the antenna cable into the vehicle, and strategies for doing so vary depending on the type of vehicle in which you're installing the system.
Passenger cars
The most common strategy is to mount the antenna on the roof, then run the cable under the weatherstripping around the back window. This often allows you to run the cable into the trunk (without exposing it). From there, you can run the cable along with the existing wires into the cab of the vehicle, all the way to the tuner box.
Source: Crutchfield
