[Jdub]

You MUST shave the head of the socket you are using such that there is no flared section. Grab a socket and look at it: you can see how most of them have a slight radius to permit quick location to (normal) bolts. In our case, the bolt is so thin at the head that you will need 100% contact: contact you can't get unless you shave the socket end.

Also, be sure to put rust penetrant on the bolt, then hit it with a nice solid hammer blow. Remember that, oftentimes, turning the bolt tighter can permit the flow of the penetrant to the threads. Once you get it going slightly, move the bolt clockwise and counter-clockwise, squirting in penetrant as you can without soiling the seats or carpet.

I have done this at the wrecking yards. Lots of patience and some treats for the yard dog or cat is the way to go!

John