Thank you all for this thread. I have mounted a Stealthitch on my Dual Motor LR M3, and am about to take delivery on a small Teardrop trailer, which will come with a 7-pin connector. I can use an adapter to connect to the 4-pin on the M3, but it sure would be nice have an 7-pin on the M3, so I could keep the trailer battery topped off. Is it possible to mount a working 7-pin outlet on the M3?
Yes. The only addition to my instructions would be to splice into the reverse wires of the taillights.