Yeah, I have done it and I would never, ever do it again. Laptops are unwieldy devices in cars, but never more so than when you are trying to sneak a peripheral glance at where you are going, only to find the problems referred to by his BEagleness.
Battery life, display size and quality, Lappie slithering around the car, having to take same with you at destination, otherwise it will be nicked by some light fingered artisan - the misery goes on and on. I found it a nighmare. Thought of a PDA or even software on your mobile phone? I went for the PDA and as written here before, I found it so good, that I flogged the laptop and have never looked back since.
Conan