I WAS TOLD AT A RETAILER THAT THERE IS A SEPARATE cAR kIT/dOCKING STATION MADE FOR THE SIRIUS STARMATE THAT I BOUGHT FOR A CHRISTMAS GIFT. THEY WERE OUT AT THIS STORE. I HAVE HAD A PROBLEM FINDING IF THIS EXISTS. I ONLY HAVE 1 RECEIVER, BUT WANT TO SHARE IT BETWEEN 2 VEHICLES. IS THERE ONE MADE?