that's an Atlas Pontiac Grand Prix, I think it's a '62. It was missing bumpers when I got it, and in that pic it's loosely screwed to a pullback chassis. The chassis I got it with had a motor and nothing else (no axles, electricals, etc.) I've since gotten together a running Atlas chassis for it, and faked together bumpers from a Hot Wheels Pontiac Bonneville... here's a couple pics. The mint green car next to it is an Atlas '62 Impala, which I got with the Pontiac, and with a complete chassis. It didn't run, though... both the Atlas motors I got were bad. So I bought a lot of 6 Lionel motors off Ebay and adapted a couple to work for these. They're can motors like Eldon and Tyco S cars.
Recently, someone i know returned a favor and cast me a pair of replacement GP bumpers, but I haven't gotten around to that project yet. My "fake" HW bumpers will come off pretty easy since they're only held on with white glue.
Can you tell I like to talk about my toys?
--rick