Ask Engadget: Best PMP with GPS and WiFi for in-car use?

We know you've got questions, and if you're brave enough to ask the world for answers, here's the outlet to do so. This week's Ask Engadget question is coming to us from John, who'd like to get his paws around a multifaceted portable media player that could serve as the main source of entertainment in his whip. "I'm looking for a 5-inch touchscreen PMP or MID to effectively replace my car stereo. My ideal setup is to plug this PMP into a dock and run the audio through the aux-in of my car. I want something I can easily take out of the car -- preferably with WiFi and GPS. I already have an iPhone, but I want something with a larger screen. Full story...