My plastic freight car challenge

[doctorwayne]

....The new owner prefers to own fresh painted models only - a thing that I can't understand.

Very nicely finished, Bernhard.

I agree that most models look better with at least some weathering, but how much is "enough" or "too much" depends on individual tastes. I think that most modellers who are capable of weathering a car would generally prefer to do so rather than have someone else do the work. This isn't necessarily because they think that they can do a better job of it, only that they feel that they can do the job exactly the way they think it should look.
If their work makes a mess of the car, or if they choose to not weather it at all, you can take satisfaction from having given them a well-built and good-looking car.

Wayne