Hello,
I got stuck with broken cable and closed trunk on my wife's E90 335D with no key hole, no folding seat or "ski sack" in the middle so I was evaluating the Kenobee option above (thanks!) and wanted to drill the hole. Did I say it is my wife's car? Ok, here is the ULTIMATE non destructive recovery if everything else in this thread fails:
- Remove the seat cushion (it's only on two clips)
- Vacuum the kids mess underneath the seat cushion (optional but satisfactory)
- Unhook the passenger lower corner of the rear seat, (you need to put your fingers between the door seal and behind the seat and lift the corner up) it's quite flexible corner so once unhooked you can pull it few inches from the body. I put a wooden block underneath to keep it opened. This will provide you a peephole to see the sexy manual latch. I also removed the two middle bottom torx M10? bolts but it did not show any positive impact on how far the seat can be opened.
- than you need literally fish the latch. After few trials I used my daughters fishing rod as it was flexible - you need to feed it between the front passenger seat and B pillar through the peephole and once clear of the B pillar you need to go up. Other option would be smaller sticks and keep adding and taping them as you push them inside since there is not enough room between the opened rear door and the peephole. You need about 6 feet long object to reach the latch. I'm explaining it too complicated, sorry, once you start you will see it.
- the hook shouldn't be a J shape but rather just an L shape because the latch is clipped to the wall and with the J shape you won't be able to engage the latch.
I hope it helps!
P.S.: I wanted to add few pictures but don't know how, I tried it via google drive links but it is not showing anything. If it will prove necessary I will do it with someone's help, thank you.