I have a Magellan GPS Tracker in my car. Garmin and Magellan seem to distinguish themselves by the orientation of their receivers. Garmin's models tend to be landscape while Magellan's models seem to typically be portrait.
I had to order a windshield mount direct from Magellan. I like the location better than Rob's steering column mount, but the stupid hardware was expensive and poorly made.
You should also note that GPS receivers don't work that well in SVXs. I had to put an active antenna in the trunk to get mine to work well. With that antenna, though, I get better reception with my GPS than I've ever gotten with the included antenna.
I had a hard time finding an active antenna with a long enough lead.