Ask and you shall recieve! (Flip Top Gas cap Adapter)
It has been a mixed bag really. I have only heard of maybe 3 at the most that had any problems. One being a good friend of mine. Its the biggest reason I hadn't really addressed the situation. It wasn't very common.
Based on the material and the design, there isnt much I am able to do without making the product in a different manner, or possibly 2 different depths, but in reality to try to account for all the different variables across 1000's of cars would turn out to be quite a hassle.
There are a host of things that can attribute to these not fitting well. Body damage, Bondo, 10 layers of paint, different filler tubes, etc...
I am willing to take a look and see if there is a viable solution. As well as see what we can do fo those of you that have an issue. :)