There have been multiple threads in the past about this.

I believe that there may be one scene with the hood up.

As him being a PI , at least the green car blends in. There is one Mannix episode in season 5 where a villain is driving a ‘71 TorRed 383 Road Runner that has a Black and Orange bucket seat interior. The episode has long shots across the mountain roads where you can see the Road Runner a mile away.