What could this be?
 

With the wealth of knowledge here I was hoping someone could tell me what this part is. There was also one on the other door too but it's missing.

Re: What could this be?
 

Taking a guess, I would say aftermarket sun shades? Is there anything at the top of the door?

Re: What could this be?
 

I can't help, but it looks very similar to a cabinet door roller latch

Re: What could this be?
 

Maybe the bracket to hold some old style beverage can holder. Used to see lots of those when I was a kid.

Re: What could this be?
 

In the late 1960's my uncle had at least one of these on his windows, it had a rubber roller on it and would prevent the window from rattling or wind noise.

or at least it sure looked like what was is pictured here(missing the roller)

Re: What could this be?
 

All good theories. I'm just going to remove it as it serves no purpose now. Thanks!

Re: What could this be?
 

You're all wrong. It clearly is a Thumb.

Re: What could this be?
 

mounting hook for a drive in movie speaker???

Re: What could this be?
 

Food tray holder at the local drive in?

Re: What could this be?
 

GM aftermarket stationary roach clip. It allowed the driver to safely park his roach so he could keep at least one hand on the wheel and take a swig of beer.

Re: What could this be?
 

Ding ding.