Good news! I have been trying to figure out which one of these is the passenger side, and which one was the driver side belt tensioner - so I took the one I broke (and put back together) - and mounted it in the passenger side hole - and it immediatly unlocked! If I had only tried that first, I wouldn't have broken the darn thing. Am going to take it back out now and glue the lid on (I broke one of the 4 clips when it blew apart - I don't want it to come apart at some bad moment in the future). Oh yeah - also - the spring was installed correctly because the seatbelt retracts like it should (it could be a little tighter, but it still works ok).