There is no easy way of obtaining information about someone who you run across but don't actually speak to. Specifically, I would love to have people go to my website if they're interested in knowing about me without even meeting me personally. To this end, my car license plate reads: "ram (dot) org". My second car's license plate is "Bioverse" (the expectation is that a user who types in "Bioverse" in Google, or another search engine, will go to my research webpage about the Bioverse).
Vehicle license plates are a natural way of letting people advertise their webpages (since the numbers are publicly visible). However, it is not possible for full domain names to be embedded in license plates. But an astute webpage owner can populate his webpages with the vehicle license number (which could be a "random" string or even a vanity plate containing a specific keyword), and direct users to the web page automagically through a search engine.
There is nothing Google or another search engine needs to do except advertise this idea. One can then have "Google this!" vehicle license plate borders to let people know that it can be used as a search term.