I can't think of any reason you would want two tuners

Well, I dunno... assuming the tuner is -- as described previous -- a box that atttaches to the cable pack and goes up under the dashboard... I'll go out on a limb and say "So I can also order a 2nd car-mount and put the 2nd car-mount and 2nd tuner in my 2nd car"?

Just .. I dunno... guessing.