SLOWING down the rust monster..........

all good suggestions. If the car is kept in a closed garage, you might consider buying a dehumidifier. I think I paid around $250 for a dehumidifier about 7 years ago. Since then, I've run it 24/7. I have it draining into the garage sink. It doesn't seem to use a lot of electricity, as I have never noticed a big difference in the bill.
That's a great idea it's also good for your tools and other equipment and toys that you may have in the garage. I keep one running in my reloading gun room.