On the winter starting thing it does specifically state in the owner's manual to run the A/C for a 5 mins. min. at least once every 30 days to keep the seals tight and oil circulated so the refrigerant does'nt leak out.
A couple pieces of plywood would also make an effective break between the tires and concrete.
If someone in your hood has bought a new fridge or flat screen ask for the cardboard and lay it out flat put the wood/styro/carpet on top of it and drive on to the "pads" the weight of the car will hold the cardboard in place and will catch and show any fluid leaks from the car and also protect the concrete from same a win win.
Make sure you have a good wash and wax done before you put it away to protect the finish.
Another good anti-moisture/mold trick is to put a few old margerine tubs half full of plain white rice [uncooked] in the car say four in the cab one each side front and rear and one more in the trunk. They will absorb any moisture in the air. If you have a really damp parking spot check and replace if necessary once or twice. Just use the cheap no-name stuff.
Make sure to lift the floor mats up so air can get around them to the carpet underneath... you can clean them and stack them in the trunk this will help to prevent floor rot and that musty stink in the spring.