Actually, somebody already invented a car using water as fuel since 1968 in the Philippines. The inventor mixes water and salt to make it a heavy water and split hydrogen using a 12 volt battery. But the invention was ignored because it can cause global war and world economy will be in shambles if water is used as fuel. Just lately, Taiwan took the invention from this guy and will put it in their cars years from now.
The technology has been there a long time ago but its a global conspiracy since every country is making money from oil.
As for deuterium, it is the British and the Japanese who started drilling it for 20 years now. I believed Saudi Arabia is backing it.