The "send" link from every Google Maps page will open a dialog that lets you fill your BMW account name and send an address plus some notes to your car. This service is free and it works only for businesses in Germany.
Google explains their partnership with BMW by saying "they're a leading innovator in the automotive space, and they share our vision for a network-connected world". In the web space, BMW's German site was removed from Google last year because it used doorway pages, but it was quickly reincluded.
Here's a video that shows how the whole thing works:
{ Via Google Blog. }