I second the 296 idea. If you don't have to have a color display, the 196 is maybe the most economical Garmin that has autorouting, which you'll want for the car.
I use mine in the plane, in the car, and on the motorcycle. I've taken several trips on the bike from ATL to KY, TX, AR, and all over North GA, TN, and NC, using the 196 to auto route to avoid the slab. Also, if I see an interesting detour, I can try it out and let the GPS re-route for me.
These are relatively inexpensive now, I believe in the $400 range. I like having one unit to use for all situations, and if it gets stolen / smashed / lost, it wouldn't be as big a deal as it would if it was a 496.