@Antoine, @sixcyl: for March I had that idea: http://www.siha.de/acs.php

@ville84: in Duisburg we just have met us randomly, because it was a oldtimer-market, we both had visited.
btw., this market in Duisburg is not worth to make a long trip for it. I'm just living nearby. For classic car-freaks and automobilia-collectors there are much bigger and more important events.