Jonas,
I've used auto touch up paint here in Oz for many years with great success - the variety of colors is a real plus, especially if you're making a car for someone and want the "right" color to finish the job - I've even had the local speed shop mix particular colors that weren't available off the shelf. I generally use the small spray cans, using a small length of straw to decant it into my airbrush jar.
The beauty of this paint is that it dries very quickly, and dries very hard, making it easy to use normal auto polish to get that "wet look" ......... it lays down very well and the coat of paint thins down a fair amount as it cures.
Just be careful - the stuff uses an acrylic thinner that contains liquid hydrocarbons and keytones - in large doses they are styrene solvents.
I've NEVER had problems with the stuff killing a car body - I make sure I use a good quality primer, laying on several dust coats then a quick wet coat and allowing it to dry thoroughly before I try applying any color coat. This coat of primer acts as a barrier against the color coat, which will normally be thinned more than the primer. Take care that you don't put too much paint on at any one time, as I've had previously sanded mold parting lines appear after applying too thick a coat.
Allow god drying time between wet coats - it's easy to complete a full body spray in a matter of hours.
Good luck!