Rust is certain, and there is really no good way to spray it inside, especially in the dead corner. Don't worry about this situation. In the northern coastal areas, it takes at least 5 years for rust to be smoothed, and it is stored in the open air. It's OK to add another piece of tin then, so don't worry about driving. Many change cars every few years! It is inevitable that the car will scratch when driving outside. Don't care too much!