Hi All,
best touch up paint is the bits that I have got with my mitshubishi 10 or so years ago, it was painted on a clear non stick sheet of plastic, hence color matched, but the reversed side it as painted with base coat and adhisive that can be peeled off, so what you do is cut out the bit of paint that you need (a little larger than the scratched).
Then peel the adhsive backing (smilar to a white out strips that you can buy from 3ms) rub the clear plastic cover until the paint sticks more to the bodywork and after x period of time, remove the clear plastic and magic!, a matched painted surface build up by the factory.
Any one that find such a product should share the source!