I've been waiting for the United Nuclear Hydrogen kit for awhile now.
United Nuclear - Hydrogen Fuel Systems
They claim that it can do 350+ miles in a hydrogen corvette using solar to provide conversion energy. With the kit you can also run gasoline, so no need to find a hydrogen fueling station.
If all of their claims are true (and if it is ever released) then I will be looking into buying one of their kits when it comes out.