These are all screencaps that I added in the comments section of other vehicles.
The first 4 screencaps can be found on the 1974 Pontiac Firebird page:
http://www.imcdb.org/vehicle_225942-Pontiac-Firebird-Esprit-1974.html
The 5th screencap is from a 3-star yellow Mercedes-Benz SL (left side 11th from bottom):
http://www.imcdb.org/vehicle_271202-Mercedes-Benz-SL-R107-1974.html
The 6th screencap is from a 2-star Chevrolet Nova from the car rental lot (notice the Mustang in both shots):
http://www.imcdb.org/vehicle_276454-Chevrolet-Nova-1974.html

I don't mind others like MaindrianPace adding vehicles, but this is one of the things I was concerned about when I started doing the show. There are so many cars in this show, especially from parking lot and street scenes. Instead, I have added many as thumbnails in another vehicle's page rather than add a page for them. I've been pretty picky when it comes to adding background cars, but I still often add 10 to 12 vehicles in an episode. Over 119 episodes, this show could end up with well over 1,200 vehicles.