It is time consuming, but as a fabric artist you must do what you know is best for the finished quilt. You care a lot and that shows, so I think you should just take your time and fussy cut the 80 cars. I do something else while cutting fussy cuts, like singing, praying, planning, etc. It certainly helps get through the cutting process.
I recently almost gave up on a Civil War quilt I was doing, but the encouragement of the ladies and gents on the board really helped me and I finished it and got some very nice comments. So please forge ahead and you will be happy you did. We want to see a photo of it when the top is done.