Fuel cells need a catalyst and a friend of mine pointed out that it was platinum, which there is not near enough if all cars were to be fuel cell. I remember that someone came up with a matrix that can go into a hydrogen fuel tank just in case someone does wreck with one. Can't remember how expensive it was.
Diesel is what will be most common. The Germans during WW2 were cracking coal into oil, synthetic fuels. At one time, they were exceeding what they used to import. So, guess which nation holds the bulk of the world's coal reserves? The US of A.
Cars will have to be true hybrids, capable of running off of fuel, or storing energy from the grid, or converting it from solar or using an inboard generator. We are not going to run out of gasoline per se, as it will be more a function of economics, i.e., really expensive.
Enough about cars, now about building. Houses will have to be more efficient in energy usage. I'm working for a green builder while my business is struggling to it's feet. He builds the exterior walls with six by twos, insulates on the outside as well, and uses double the amount of insulation you would find in a normal attic. Everything is caulked, plates, sills, siding, outlets, sheathing, subfloor.....everything. Place is like a submarine. It really does need an air exchanger.
Plenty of energy out there, just that it's not going to be pumped out of the ground as much.