What should I wear for an interview at ZF TRW?

Typicly you want to dress business professional. Since every hiring manager has different expectations, it is safer to overdress a little. I personally care little as long as it is neat and clean. In some rare circumstances I hired a brilliant person who was just socially unaware and looked quite tattered. But for most mere mortals, you should try to not disappoint with your attention to social conventions.