Here's what happens on my 2009 R57 base convertible:

1. Sunroof slides open (always works). Both sides seem to be in sync.
2. Top goes down (always works).
3. Latch claws advance but then either
   (a) passenger side doesn't quite get there, and I have go back up and try again, or .
   (b) both sides lock in properly and we're ready to roll - yeah,
   (c) they appear to lock in properly, but still the "top not locked" icon appears & dreaded warning chime occurs at 20mph+, killing my convertible buzz,
   (d) they lock, but then the edge of the top goes forward right into the roll bars. I have to release (unscrew) the little receiving docks the latches attach to. If I'm really unlucky, I have to disengage the hydraulic pump & put the top up manually.
4. When I try to put the top back up, it mostly works, but sometimes the latches won't release, as in (d).

Two Mini dealers couldn't work it out & wanted to replace the whole top at major expense. Thanks for the $175 "diagnosis", guys. One mechanic said it was just a timing issue; his fix held for 6 months, until it regressed.
If I could retime the mechanism like he did, or reseat / replace a hall sensor, or even just turn the damn alert chime off, I'd be ecstatic. There's nothing sadder than a convertible that won't convert.

 

You have a 2009. Do you have the plastic side clips that would always break (which then triggered a top replacement)? They are on the sides, unsure if that would affect the latching (not aligning?)

 

Did you see this thread? https://www.northamericanmotoring.co...t-working.html

https://www.northamericanmotoring.co...tible-top.html

You might be able to get the top at a junk yard if its bent. Sounds like the latch system which you cant really replace, Here is all the parts.

https://www.realoem.com/bmw/enUS/par...Cooper_S&mg=54

https://www.realoem.com/bmw/enUS/sho...diagId=54_0407 #9 you cannot get on those and #1 includes all those moving parts/most of whats failing but its $$$$, thats why used might be best.

 

Thanks for responding Scott. Are you referring to the clips that hold the trim? Because most of my trim is gone after those clips broke! There's no trim on the right hand roof line, one piece left on the left and the crossbar at the top has gone too. Doesn't seem to make much difference either way.

 

ECS Tuning thank you for weighing in, very kind. I did look at those forum postings, and none of those problems seem like mine, for better or worse. My Cooper craps out at the last part of the sequence, which implies that it's not getting the right signal from the hall sensor, or that left and right sides are out of sync, or maybe that one side is getting caught on something. But I'm no expert. I can get it right when i guide the right side in, but it takes me many stressful attempts to get there (and I worry that I'll break it completely!) .