Tucker and I LOVE the Outward Hound Lookout Seat which you can see here at
http://www.petco.com/product/12262/O...ster-Seat.aspx It's easy to put in and take out and it's simple to clean. We just hook his harness onto the clip and he can see out the window or curl up and snooze. Car rides are no problems with this seat.
I bought mine for about $22 at Petsmart.