Susanne Oberbeck sings sexually charged songs in a German accent while standing topless and sporting a moustache " and at last she's found an audience that understands her In 2003, Susanne Oberbeck saw a headline in the Sunday Sport referring to a member of S Club 7. "Rachel Stevens," it said, "with no bra." Oberbeck, who is German, was sufficiently intrigued by this sleazy tabloid prurience to name her own band No B…