i don't know about "webshops" but if you tell him to contact the guys over at rz motoring (
RZ Motoring ) they can source a ton of hard to find parts and might be able to help him out or at least send him in the right direction
-james
::edit::
just realized your in Germany if he is also that shipping is going to be a bitch. rz is in tampa and orlando Florida. hope that can help him out