1 kg of Hydrogen has 36 KW-Hr of energy content.
5 kg of Hydrogen is sufficient for a 500 km driving range which is typically about 10 days of usage. So a typical car would consume 0.5 kg of hydrogen per day or 182 Kg per year
A molten Salt reactor would typically burn 1 tonne of Uranium per year.
1 Tonne of Uranium has an energy content of 240 MeV * 106 * 6 * 1023/238 = 6.05 * 1029 MeV
This is 9.7 * 1016 Joules or 2.7*1010 KW-hr
The themo-chemical water cracking process is projected to be 80% efficient in converting heat energy into Hydrogen so this energy creates 0.8* 2.7*1010/36 = 6.0*108 Kg of Hydrogen.
This is sufficient for the yearly needs of 6.0*108/182 = 3.2*106 vehicles.