[Wildcat]

OP is long gone, but after reading through the Ridgeline forums, it is not as easy as just adding the cap--there needs to be some sort of baffle to keep water from getting behind the fuel door. What was happening in the Ridgeline was that water was getting into the cap, freezing the door shut, and owners were finding they couldn't refuel in the winter. Finally after a year or two, Honda decided it was a problem ? and issued some new parts with a baffle that clipped into the fuel door to keep the water away from the cap.

Other manufacturers have had issues with those types of caps also. I would only hope there is one out there that is immune to freezing.