Allroad trailer hitch

[motogo1]

I know this isn't the allroad list, but I bet some of you guys got one. I
recently bought an 03 and had the dealer install the factory hitch and
electrics. Problem is the connector is 10 pin. I need an adapter to go from
10 pin to a flat 4 pin. Local trailer place says 'we aint never seen one of
those!'   Any help here.

Gary Martin
94 UrS4
91 200 TQA
03 allroad 6 speed....I like it!!