If you haven't found out yet, this is a common 850 problem! The only way to open it is to take a hack saw blade, pull the door open as far as possible then cut the door latch. I had to pry mine open breaking the handle and locking assembly - now I can't find a used one the right color...

Yep, I had same happen a few months ago. But I did the stupidest thing of all-I trashed the lid, thinking that I would pick one up at a wreckers. Guess what-about one car every 18 months is wrecked in my city, so it's play a waiting game or pay for a new one and I'd hate to know how much they cost. Taking the stuck one off was a difficult task (and heart-breaking)in itself. I drilled around the lock, but the lid has many layers and is very hard to break into. Find that explaination of how to saw the latch. Don't what ever you do wreck that expensive lid.

Cliff, this comes up fairly often here on the board. I believe the latch mechanism fails. I'm fairly certain that the only fix for this is to saw through the latch catch with a hacksaw blade and then replace the affected parts. I do remember other posts urging care while prying on the door with one hand and sawing with the other. Maybe some carefully positioned cloths would help.