[A]n unwritten contract is not worth the paper it isn't written on.

Whittington v. Indianapolis Motor Speedway Foundation, Inc., No. 08-3352, slip op. at 9 (7th Cir. Apr. 14, 2010) (holding that man who claimed to have loaned 1979 Kremer Racing Porsche 935 K3 failed to prove ownership) (Kanne, J.).