The fuel companies now have an HHO generator in U.K announced & shown publicly for first time this week.
The generator cost them $3000 & it fills cars with HHO on demand.

Problem is they can only run car for 40 miles between fills due to storage problem... car can then switch back to petrol.
They also showed the BMW only available in Europe which runs solely on HHO.

I think my HHO generator is far advanced to theirs... & I have the added incentive.. Predicted petrol price announced today here in 2014 to be $8 a litre ($28 U.S. gallon)