Keeper of the Flame (1942)

Here's a link to the trailer for the movie, which shows the car crash. I'd be willing to bet the final crash scene is a model, they didn't have computer graphics back then of course, but they were pretty accomplished at making models look real.....

You may have to skip the first preview....with the "skip" button on screen.....

Trailer #1 Scene from Keeper of the Flame Movie (1942) | MOVIECLIPS

Thank you, sir. Been ages since i saw this flick. On close study, looks like the car that flies off the washed out bridge just might be a model, tho' better than most. Remember 1933's Invisible Man with Claude Rains, and marveled at the well done model train that similarly crashed.

Now, if only we could see some stills, or the funeral scene of the title character with that Connecticut village square ringed with big formal Classics. From memory, it looked like a late model Packard Twelve car lot.