I put a couple of silica bags in the trunk and in the passenger's side to make sure no water vapor is allowed to accumulate. I change these every couple of months. I also soak two sponges with leather cleaner that has a leather odor to them. In addition, I put the car on plywood that is covered with carpet pieces. I use sta-bil and replace my oil and filter just before their long winters nap. Needless to say they get a total detail before storage. My garage is heated so I keep the temp at 50 degrees. On the roadster, I put a blanket on the top before the car cover. Since I only drive in good weather I put the top up for the winter storage. I also use the battery tender mentioned earlier. I also replace my brake fluid. Most important take them for a long drive before storage.

P.S. I take the antenna off the roadster.