Have a trailer hitch on my E30 to pull a small jet ski trailer. Then put a hitch on my Mini Cooper. The wireing is not complicated and there is ample space to run the power from the battery to the rear plug. Both of those run the wires at the drivers door under the carpet. There are a number of suitable wire holders from BMW that make the job easy.
The 4130 molly custom tow bar on my 1967 S is outstanding.
