I admit this not a critical thing, but I would like to have it fix as fast as possible. Any ideas how to change it back without going back to the dealer? I searched the archive but no answer there.

It's in the FAQ titled "Coding the Control Module II"<ul><li><a href="http://www.a4.org/faq/faqs/faq96.shtml">Coding the Control Module II</a></li></ul>

Based upon your driving habits, the trip computer will revert to various languages around the world, including Albanian and Esperanto.