So far I've used my Meridian Platinum in my Saturn and in my GM Venture (mini-van). I get fine reception in my Saturn, which is good since it's what I normally drive. However, we use the mini-van when geocaching on the weekend since we're hauling the kids and the dog. The problem is I see the satellite reception drop drastically as soon as I bring it into the car. Since the Platinum doesn't have an external antenna, I'm wondering what my other options might be to get good signal.