The vehicle history only goes back to 2000. But its a nice site for comparing impact of vehicles.
My 99 Contour 6 cyliner automatic DOHC on a scale 1-10, 10 being the highest:
1 for air pollution (ugh!)
5 for greenhouse gas (see comments on 1)
Thats figurung with a 19 mpg avg fuel economy for my car. With your guys help I've gotten up in the 30's. So I'll bet I would show a little higher than a 1 and 5.
Anyway take a look at the site, its pretty neat.
http://www.epa.gov/greenvehicles/Index.do