Came accross this site that plays movie trailers www.IMDb.com , put in thunder road and and punch go, then punch thunder road 1958 it will play the original promo for the movie, its pretty funny how they show robert mitchum driving a 51 ford from the inside than they show him from the outside and its a 49 ford then it changes to a 57 ford, good action shots of 57,s .
I have a tape of that movie, and every time I watch it I notice something different. There is one shot of the '49/51 that shows the door open, the key is on the left (51) but the outside of the car is '49. It was a put together car of some kind. In the beginning of the movie, Mitchum makes a high speed U turn and rolls the car, and it emerges from the dust heading the other direction with nary a scratch. Later in the movie, he gives the '49 to another whisky runner and buys a new '57.
John