This is me (not your GF obviously) but having a horse etc. lol I have an Audi convertible and my ex gets so disgusted with my car that he still washes it now and again but he has OCD as far as his car is concerned.Mrs C has a horse and drives around with half a farm yard in her car.
My wife Kerbed my brand new a4 19" rotor wheel within a mile of her driving it on the first night. After multiple swear words and a few minutes of silence, I got the "it's only a wheel" response. Some more silence involved and almost a tear down my face
That's exactly what my wife says.
"It's only a car.
Easily remedied this,
Jack prestigious automobile up and remove wheel,
Call nuisance wife to dark secluded area of garden,
Show damaged rim to offending said woman,
Listen to lame excuse and count to 10,
Beat said ungrateful woman within an inch of her life with afore mentioned alloy device!
Job done, recycle said woman!