Humidity in the air.
it will rust
Car magnets doesn't cause rust.
When your car stalls when its raining, it may be getting water in the distributor cap. Make sure the cap is on properly.
NO! That is extremely dangerous and you could get electricuted! Just go find a place to stay until it stops raining, or stay in your car, and jump start it when it stopped raining.
When I am in my car and it is raining I might hydroplane.
rust can dissolve the metal on ur car then ur car can fall apart and it will wreck your paint
If you are new to the concept of car rust, http://www.dummies.com/how-to/content/how-to-protect-your-car-from-rust.html is a great article on a beginner's guide to it.
The temperature inside the car is higher than outside
The best way to remove rust from a chrome with bodywork is to take your car to an autobody shop. They are the best people that can remove rust from chrome.
When salt and water and air combine, it accelerates the oxidation, therefore making the car rust faster :)
There is no rust remover that going to repair the rust that has accumulated on a car for that long. It will be best to have the floor repaired by a professional.
To keep occupants from falling out of the vehicle. It also protects you in a side impact. Also keeps the elements out of the vehicle. Without a door you would be very cold in the winter and hot in the summer. You would also get wet when it was raining. Lastly the interior of the car would get wet when it rained and would rust out very quickly.