I've done a bit of testing and it appears that I have a leak on the passenger side seat. I can hear an air leak underneath when air pressure is applied. I was able to get the driver's seat to lock by blocking one of the vacuum lines on the relay valve under the left rear seat. I need to remove the passenger side seat to get a better look at things underneath but it is proving rather difficult. I've managed to pull a few bits of the plastic trim to get better access to the front 10mm bolts but the one on the right side won't come free. I don't want to break any of the plastic that surrounds the seat base. I sat on the seat and tried to loosen the trim but that did not work either. Am I missing something here?