Parts with fuel going through them

[Grimhof]

Maybe make it so parts with fuel going through them are not destroyed instantly when they hit something hard, they would leak and you would have to repair them. This would affect fuel lines, fuel tanks, and engines.

The animation could be it dented or a tube sticking out and a mist spraying.

[Sirrobert]

With the exception of decouplers/seperators, all non engine parts can crosfeed fuel