Flip Top Gas Cap Conversion

I have one on my Duster.

You have to drill the holes for the adaptor. Not all the caps are the same, not all the bolt patterns on the cars are the same, and some people have real heartburn over drilling extra holes in their cars.

The holes for the filler neck and the holes for the cap don't necessarily line up in a place where the cap is properly oriented on the car. Which makes sense, because if you need the adaptor you're adding a flip top cap to a car that wasn't intended to have one. You can overcome this by either drilling the extra holes into the car, drilling the extra holes into the cap, or, if you REALLY have an aversion to drilling holes into your car or your cap, you can countersink the pattern for the car into the adaptor, bolt the adaptor to the car, and then drill the holes for the cap into the adaptor and stop short before you drill into the car. But then the delrin is the only thing holding the cap on.

I just used the cap as my pattern, put it where I wanted it on the car, and drilled straight through. No matter what happens, its under the cap.