Designing and making cars differently and emphasizing ultralight weight, ultralow drag, and integrated design can reduce required propulsive power by about two-thirds. This can make direct-hydrogen fuel cells and commercially available compressed-hydrogen-gas tanks practical and affordable even at relatively high early prices. Coordinating such vehicles with deployment of fuel cells in buildings permits a rapid transition to a climate-safe hydrogen economy that is profitable at each step starting now. New manufacturing and design methods can also make these radically more efficient vehicles cost-competitive and uncompromised, as illustrated by a 2.38-litre-equivalent-per-100-km midsize sport-utility concept car designed in 2000 by Hypercar, Inc. Major reductions in the required capital, assembly, space, and product cycle time can offer key competitive advantages to early adopters. These changes are increasingly recognized as portents of unprecedented technological and market transitions that can make cars climate-safe and the car and oil industries more benign and profitable.