Jerry mentioned the indash versions. We also checked the one in the Volvo and it's the pits. It comes up out of the dash and at least half the time you wouldn't be able to see it because the sun would be on the screen. We were generally underwhelmed by it.
Regarding the interactive GPSs, the passenger should be able to work the darned thing while driving. That's supposed to be what makes it useful; e.g., deciding on the spur of the moment that you want to find, for example, a restaurant or mall and being able to change course immediately. Without that feature, their usefulness is reduced significantly. And, by the way, we have never used them in conjunction with a laptop. Just too dangerous. Get the kind where you can download the needed maps from your computer and you won't need to use the laptop.
The GPSs have improved significantly since our first one and I love them!
ArdraF