This is a 1941 Dodge:


This looks like a Dodge Coronet:


This one is a Rambler:

But it's a Rambler American.

http://www.imdb.com/title/tt0058815/

http://www.imcdb.org/movie.php?id=58815

Not so many cars in season five, the show's final season.

5.8

Chevrolet Pickup, one star


1967 Dodge Coronet?, one star


1969 Ford Custom, two stars


5.9

1970 Pontiac Bonneville, two stars


5.13

1969-70? Ford convertible, one star


5.14

Rolls Royce, two stars


1941 Dodge, two stars


5.26

Cadillac, two stars


Imperial, one star


car on right, in foreground...Buick? one star


Plus, I do have a couple of leftovers from earlier years, I initially didn't add because they were small, blurry, etc.

Opening credits, eps. 1.1-1.8

Renault Dauphine, one star


1.9

1963 Plymouth (Savoy?), one star


3.14

green car in foreground...Rambler American, one star


4.12

on left...Pontiac (Bonneville?), one star


1961 Chevrolet, one star


Buick (Special?), one star


In season five, Roger Healey drives what appears to be a green 1970 Pontiac Firebird convertible with a Yenko-type white striping package. Unfortunately the shots of this beautiful car were lousy, just "part seen" images. The first is from ep. 5.15, the second is from the very last episode, 5.26.