Ford provided the wiring from the dash to a pair of connectors at the rear end of the coach. It was up to the coach builder to extend the brake controller wire to the hitch connector. The place for you to start is to look at your coach's hitch connector. How many pins does it have? How many pins are wired, and which ones?
You should probably also contact HR and ask them about this and at the same time request a set of wiring diagrams for your coach. They should send you a CD with them on it.
I assume that you've already determined that the combined weight of the trailer and car will be within the towing limits of your coach, and if not, what modification strategies you plan to follow. For instance, I'd expect the hitch to be rated at 5,000 pounds.
Let us know what you discover with the hitch connector.
2008 Holiday Rambler Admiral 30PDD (Ford F53 chassis)
2009 Honda Fit Sport