oops. didn't see this until now.
I have had 3 hitches custom built at TorkLift in Kent. They will work with you on exact wishes/specs. I had mine for both Audi and BMW wagons made flush fit up into the rear valance so as to allow 100% factory departure angle/clearance. Neither required drilling into the car anywhere. $350-$550 depending on various things but I also had mine reinforced beyond what most people would request.