if you want to plan your route on your computer and then load them into the GPS... you'll have to go with a Garmin that's got a model number higher than 700. just FYI
I do have a E-Trex Legend that will do that too... cost me about 250... but for a car it's display is on the small side... as it's main purpose is hiking.
I know Trip recently went through a little issue with car GPS's... you might pm him. or he could stop being a bitch and chime in...