IMCDB has a listing for Proof, shown as a 1991 movie. It includes a 1968 BMW 1600-2 (3 stars). http://www.imcdb.org/movie_102721-Proof.html

Is this the same Proof that TV Guide shows as a 1992 movie starring Hugo Weaving, Genevieve Picot, & Russell Crowe?
http://movies.tvguide.com/proof/128942

Except for a few cases, every film entry in the IMCDB has a link to the corresponding entry in the Internet Movie Database - click on the IMDB icon next to the title.

In this case, they are the same film. The release dates page for Proof on the IMDB shows that it was released in the US in March 1992, which explains why TV Guide give the year as 1992.