This was a Flintstone body on a custom Futura frame, I used all the Futura parts I could ie: interior steering wheel, windscreens.
I use real metal tape on the screens, I used to use foil but the metal tape is so much cleaner looking.
I also use metal tubes in place where the axles sit in the frame to raise the car to the proper height so the tires will fit, roll and just plain look more authentic. Real aluminum rocket tubes.
The car is painted with auto primer, color coat, striped and then shot with multiple heavy clear coats for a glass like shine. and you can even wax the car without worrying about paint coming off.