Just to be clear... if you go with the U Haul, you should still get the BMW wiring harness.
In my research I find that the U Haul guys do not have a clue about wiring the BMW.

Ole Bubba said to me, "no problemo- I'll find 12 volts and we will be ok". I mentioned the computer and the Hall effect brake light system, then the 5 volt multiplexer system... he said maybe it would be better if I went somewhere else to have the wiring done, after I mentioned his liability if he messed up the computer.

False ecomomy....