My cousin saw it this morning in her way to work which is when I saw it..

Mel - DH looked at and said that it looks like paint etc from the car, not an actual scratch in the wall.. So will suggest gumption to my cousin tonight. Does it remove colour from the wall?

I get what you are all saying about wear and tear, and I feel the same (maybe this is classed as a little bit more), but I am more scared of my cousin (we normally get on well, but some things she nags and nags about, and this is one of them) than any real estate or money to fix it..