While driving on the highway yesterday, my airbag light came on (spontaneously). I washed the car prior to leaving (just exterior, no vacuuming) so maybe it had something to do with it. Anyway, light won't go off and from what I read it can't be erased with a regular obd scanner. I figure this is a good time to buy one of those obd cables so I can tinker with those dealer style programs (INPA, DIS). I can hopefully program my convertible top open with the key fob , and find the source of the airbag light. Car is a 2006 MCS conv.

I found some cables on Amazon but I am confused. They all seem to be similar (even identical) with varying prices. Some have a switch, some do not.
Here is one thats pretty cheap It says it will work with an R56 mini though
Here is one with a switch Also say R56 "new Mini". Will any of these work? Do I need the switch?