This neat little script modifies the Mobile.de "Vendor" address so that it links to a new tab or window with the address of the vendor as Google Maps destination.

With modifying the third to last code line, you can even have this script show up the route from your home to the vendor address, which is interesting when you are looking into the whole of Germany for a car. Just replace the q= in the query string with daddr= for destination address, and add a saddr= as start address.