but seriously it's a bit disappointing that people are unaware when buying them unless people like you & I are able to test them. Just today, I've just been sent another bypass from a 5 Series owner on a different BMW forum that he got from another eBay seller and again it's UNOCCUPIED. It's just wires wrapped around the component inside and it's not even complete as it's missing components! I've even got links to a thread on another BMW forum where this seller actually asks for a solution to the OCCUPIED issue (from last year!) but I'm not sure if I can post the link on here.
either they don't have a clue, or purposely do it or maybe they know if it's OCCUPIED that it sets off the seatbelt warning in some BMW's so they don't want to support that as they don't have a valid solution. You can't use a seatbelt insert or leave the seatbelt in for the MOT as that would fail! Good news is that I know of 2 ways to bypass this also that do pass the MOT and I think I'm the only one as I've never found anything anywhere that shows the solutions
as for the pre-tensioner, you could replace the cable yourself to be honest as long as you disconnect the battery. In most BMW's, it's just 2 wires that run from the buckle area to the main plug under the seat base. If you'd like to do this or know a little more then just say as I can call you if you PM me your number