But the upstart German filmmaker Maren Ade employed an especially unconventional technique in greeting the stars of her new picture “Toni Erdmann” for the Romanian portion of production. Ade showed up at the down-on-its-heels Bucharest airport as an over-the-top character – tricked out as a goofball mogul, pouring Champagne wearing bathroom slippers in the back of a white stretch limo.