'92 Buick Roadmaster Estate Wagon

How do you lock the rear window? Seems like it goes thru the motion of locking but when I depress the lock on the tailgate it pops right open. If I put the key in the lock and turn clockwise it feels hard to lock. Then I can't get the key out. Could the key lock be broke or what?

First tghing I would try is to lubricate the lock with WD40 or graphite powder, or similar product made for lubricating locks. Put your key in and try to turn it both ways and slide it in and out a few times to make sure the lubricant get dispersed properly.

When I turn the key to the right (clockwise) shouldn't I be able to remove the key? Even with the key turned i can still push in on the button and unlock the window. Its hard to push in tho.

On my 92, I turn to the right to lock the tailgate, and left to unlock and pop the window. Seems I am able to remove the key if turned towards the left or right. I always figured you turned left or right depending on what you want to do, then return to middle before removing key. I usually open the glass and push the lock down to lock mine, or use the power locks on the front doors. In fact, when you asked the question, I had wondered if it was even possible to lock the gate/glass with the key. So it's possible that I just did this for the first time in 9 years.

I also found that without a key, you need power to the tailgate to get the window open. Very inconvenient if you are parts searching at the salvage yard, where the batteries are always gone. I never have figured out if it can be done, buy I have heard suggestions of somehow using a 9v battery for the purpose.

I just can't figure how to lock the rear window. Thought maybe i was doing something wrong. It's locked when in drive.