If you remember, I had a back seat that was locked into the down position due to the seatbelt being locked up. To make a long story short, I decided to give up on accessing the back of the seatbelt assembly and decided to tackle the bolt holding the bottom of the seatbelt on again. I couldn't get an alan wrench to fit (probably because it's a torx screw), and after trial and error I found that the bolt is a 5/8" bolt (not a metric size, 15mm wouldn't fit, 16mm was too big). So, I got the bolt off which released the seatbelt and the backseat is now fine (with the seatbelt reattached).

As for the RPM sensor, my car had died a few times in the past couple of weeks while driving down the highway, restarting after a few minutes. I changed the RPM sensor, it really was an easy job once I found it (turns out you can only see it from the driver's side, if you are looking for it a tip would be to look for the plug along the firewall near where the fluid washer tubes join, then follow that wire down). Took maybe 5 minutes at the most, the 21" of extensions, universal, and 3" of extensions with a 10mm socket was right on the mark.