Cover looks nice, but can't fully cover my Ford F-350. No instructions on how to use with exterior antenna. Where to cut the hole, if one does cut a hole would that void the warranty. I did get 2 small square pieces with holes in them: GREAT! How to measure for cutting the 1/2" hole, you have a 3'high antenna. How do you account for centering the hole anywhere near with the cover draped up over the antenna. STUPID