Well, the "Full Cleveland" is most appropriate when shopping for large up-scale sedans (S63, 750Li, S8, etc.).
If, however, you are looking at something more sporty (Porsche, Ferrari, Lamborghini, etc.), then I'd suggest showing up wearing a fire resistant race suit (boots and gloves) and Snell SA2005 rated helmet. Just tell them you want to take it to your "banker" for an hour or so to discuss "financing".