This past summer I purchased the Base Gasket on eBay that dedwards0323 provided the link. It fit and worked perfectly. Unlike others on the forum, I removed the antenna completely so that I could remove the entire old gasket. The old gasket on my Crossfire was not just a ring like the new gasket. It pretty much covered the whole area under the base except for the hole in the fender. The hardest part was aligning the gasket to the bottom of the base and keeping it in place until tightened down. I removed the side panel in the trunk to make it easier. That also gave me the opportunity to check the level of the top cylinder's hydraulic fluid reservoir. I used a deep well socket to remove and tighten the nut on the bottom of the antenna. I think it was a 22mm, but not sure. It took me about 45 minutes from start to finish. I didn't hurry and even waxed the fender under the base while it was off.