Painting a 1:1 scale car

Hey guys has anybody used their modelling airbrush to touch up the car??

My GF is selling hers and i'd like to sand down some scratches and use the little touch up paint pot (which oddly looks just like a velejo pot)

My questions are? can i thin it? with what? surface prep? drying heat? or just dust free.

if hasn't got wings i don't know much about it....

well i can put out 60 PSI and spray a wide area, the scratch is only 5-6cm long ???

are you saying its not wise?

I have used my airbrush for 1:1 touch ups and have great results. I grazed down the side of my car under the rear bumper. I went to the paint shop gave them the colour code and they mix up the paint (Metallic red). Sprayed it on the same as a model and the gave 2 coats of clear.. Buffed it out and all good