ello pete
Right, my rear lock started to "lock up" excuse the pun last week. WD40 did help but soon went back to "lock up".
I think this problem is due to a lack of a cover for the key hole, well in my case anyway. All sorts of stuff can get in there.
Pete, does your lock move alittle bit but no way near enough to "click" it into place? mine did move a tiny bit but no where near enough.
The way i fixed it was to take off the rear lock and completely grease the baby up, this allowed for much easyer turning of the mechanism. It now works great, and turns easyly, i also greased the connecting rod ends which fit to the lock and the lock release mechanism.
Getting off the lock is not too hard, you do have these 2 white plastic clips that hold on the "rear handle" which where a bugger to get off but i wedged a screw driver in one side and pulled like hell and it budged...eventually. Theres also 4/5 bolts that hold this "handle" on which are hiddenish through the holes in the body that you can see once you take off the boot plastic covering. It aint to hard a job, do it! you will also find out if it has been glued.
My car is a Bravo 1.8hlx 98s