HAMBURG/BERLIN (Reuters) – The man Volkswagen (VOWG_p.DE) lined up less than three weeks ago to head its North American business resigned on Wednesday, dealing a blow to the German carmaker’s efforts to recover from a scandal over its rigging of U.S. diesel emissions tests. News of the resignation of company veteran Winfried Vahland came as Germany’s Spiegel magazine reported that at least 30 Volkswagen managers were involved in the test cheating. VW said the figure was without any basis.