I had the back seats down and when I tried to put them back I pushed the red tab down and now the latch is stuck. The bottom part of the latch mechanism spins but the top latch won't budge. I tried pushing the "shoulder button" back in place, but it's stuck and the seat won't latch in place - it just bounces off.
seat latch lock stuck on 1998 Volvo V70 XC
Sounds like the "plastic" piece your pushing has popped off the metal lever underneath. This requires some maneuvering but you can remove that plastic piece by removing all the Torx screws then gently remove the fragile plastic trim. Once you remove all the plastic over the seat, see if you can put the seat back upwards, if not then you might need the lock mechanism or try to lubricate it as best as you can. Oh make sure your seat belt isn't locking in place thus impeding your seats from locking. :-) -Sam