I have a 2006 3.0i X5 that I want to install a hitch. I have a Prestige trailer with a flat five-wire connector instead of the more common flat four-wire connector. The fifth wire disengages a solenoid that otherwise locks the brakes when backing up. I want to install an OEM hitch on the X5. Will the BMW OEM hitch and wiring harness work with the flat five wire connection?