I am right next door to you in Indiana 28 miles North of Indy, so our weather is very similar. I raise hay to supplement my income so I have become somewhat of an expert on the characteristics of moisture and condensation over the years. I have also had to store my car outside for long periods of time before getting a shop built. You need to get it under the carport and cover it with a good breathable cover, if it can't breath it will collect moisture and rust, even if it never had a drop of rain on it. If you don't drive it in the winter I would get it up off the ground (a few inches)and put a layer of moisture barrier (4 mil plastic would work) underneath it as well to keep moisture from coming up through the ground. A good cover can be purchased through several vendors I got mine from classic industries I believe, cost me about 150.00 if I remember right, a good investment no matter where you keep your car.