The bottom of your vehicle's doors will trap dirt and water, especially if the drain holes get clogged, causing corrosion and rust to build up and work its way out. Once you see bubbles appearing through the paint on the outside of the door, it's too late - the rust is taking over.  You can stop it, though, but replacing the lower door bottom or door skin with a new rust repair panel from Raybuck.  These panels are replacements for what's on your vehicle, allowing you to cut out the rust and replace it with brand new metal.  Once installed, coat the inside of the door with a good cavity wax or innerpanel coating, and say goodbye to the rust.