Fuel filler cap is going to be another area to go in the future, same as the old Ford Ka's. Water is always sitting in there.
Not the fact water sits there (in the recess) but all the road dirt/salt/cr@p sits on the fuel filler/breather pipe at the back and never dries out the metal flex's differently to the plastic, dirt erodes the paint water gets in and bingo nice fresh rust......
Treated my GP to a healthy coat of this in the exposed areas....
