I live in FL and with the summer heat kicking in I have had this issue now a few times over the past few months (just got my '07 650i Convertible 5 months ago).
I have read many threads and info from other places, and found a workaround for this issue that I have not seen posted anywhere else (at least it works for me).
I've had this happen to me just this morning again (car was parked in the airport garage for a week, and after taking the red-eye back from San Francisco, I could not open the trunk, and noticed the "red convertible top blinking light" problem - last thing you want at 7am after an overnight flight.
So I did what I've now sucessfully done over the past month when this happened, the the light stops blinking right away, and things are back to normal.
So this is what I do (old school):
There's a bar (not the kind you're thinking about) with an elbow that runs behind the canvas in the back pivot point in the convertible top (forgive me - I don't know the technical terms), but the first pic shows what this looks like on the drivers side. I have drawn the approx location of where this bar lies with a red dot indicating the pivot point where the faulty sensor lies.
All I do when I run into this problem is to apply a little pressue to that pivot point with my hand (as indicated by the red dot in the pic) and the red blinking light stops blinking, and things are back to normal (shown in the second attachhment). I normally push the pivot point down towards the body of the car - not a lot of pressure is needed at all. To quantify, if you press hard enough to break an egg, it's to hard. All it needs is a gentle nudge for the sensor to engage (is my guess).
I'm assuming in my case the problem lies with the sensor on the driver side, because I never had to do this on the passenger side, but it may be that in some cases one will have to do this on the passenger side as opposed to the driver side (as shown in the third attachment).
Let me know if this helps anyone else.
This works fine for me, so I'm not planning on taking the car in for this to be fixed, since it does not look as if the successrate in addressing this is that high (and I can't do without the car for two days, and it's out of warrantee anyway).
Last edited by boesman10; 06-17-2011 at 12:38 PM.
Reason: finish and add pics