Retracting sholder belts in a '69 Firebird
 

We put a lot of miles on our '69 Firebird every year and just having a lap belt seems a little un-safe.
I have been giving this some thought for a few years and thought I would give it a shot.
The retractors are out of a 2000 Grand Am and the receivers are 2008 Grand Prix. The install required no cutting or drilling on anything visible, I could put it back to original without any "damage".
I know they might not be as effective as specifically designed devices but I think they would do some good in the event of a crash. The weak point is probably the seat-back attachment which is also from the Grand Am. I suppose I could submit it for crash testing.......

Forgot mention that what got me thinking was an accident that a friend was in where the steering wheel stopped his forward motion. The car was fixed before his face healed!!
When he had the car put back together he had shoulder belts.