If you are thinking of having them install a trailer hitch and wiring to your vehicle...DON"T.
I asked them to install a 7-pole connector. They did, but they only connected four of the circuits. When I explained to the technician that I needed the purple circuit connected so that the hydraulic brake over-ride would work on our boat trailer he told me that a hook up for electric brakes is an extra cost and he would have to order more parts. I explained that I do not have electric brakes it is a brake over-ride. He did not seem to understand what this was and proceeded to tell me he knew everything because he had been doing this for two years. This connection that I needed does not require any extra parts, it is just a matter of connecting the purple circuit into the reverse lights on the vehicle. Neither the manger nor the technician were familiar with this very common trailer setup.
After taking a closer look at the workmanship we have found that the whole thing is just a "hack-job". If you value the electrical system of your vehicle take it to someone who knows automotive wiring. I wish I did, now I am paying someone else to fix the job that U-Haul did.