My friend has the Delphi unit, which you can buy many different kits for.  There are kits for a car, for a home stereo, and there is a speaker setup which this unit fits into for a "boombox."  He has the car kit for use in a car (uses a magnetic antenna the size of a large egg) and the home kit which plugs into his stereo.  The home kit has an antenna that looks like a fin and must be put in a window for it to work.  Its all line of sight stuff, so we'll lose signal downtown, or when going under a long overpass/tunnel.  However, there is a buffer (4 seconds I think) that helps with that.