Originally Posted by TJP
take the antenna off, Install the cover, mark the spot. Remove the cover, make the opening ( round preferably). Advisable to iron on reinforcement patches around the opening on both sides. wink beer
This is what I did on an outdoor car that I bought a California Cover "weathershield" to protect. They supplied little patches for antenna cutout but as mentioned, they would not cut for me.

Facts are stubborn things.