If you need an external antenna it will be a few more bucks(75-90$) but the 76c has the option to use one so if you find that the unit doesn't work well in the car you can get the antenna for it. (Doesn't come in the auto navigation kit).
I have a Garmin Gps Map 76 cs and I like. I have the whole state of Michigan in the unit in City select and Topo Plus some of Canada, Ohio and Indiana. Pretty handy when you don't know where your going. The autoroutting feature is a handy tool. If I'd of known I would of bought one alot sooner.
Look at the website http://www.gpsonsale.com for prices. They seem to have the best prices on the Gps units, I shopped elsewhere for my accessories though.