dont know much about the hydrogen car, ill ask later today

as far as the boss mustang you're refering to, its a v10, rather then a 10.0 l displacement. if my memory serves me, its an all aluminium 5.8 liter aka boss 350.9 cid. it pushes 430hp/ 405 ft. lb. , and is 0-60 in 4.4s.
the car would be much faster if it werent for excessive tire-spin at takeoff until 3rd gear is reached.
as far as production possibility, very unlikely. however, a bored and stroked version of the same v-10 is placed in the shebly cobra concept shown at NAIAS. its displacement has been increased to 6.4 liters, and 605hp/550ish ft. lbs. this is the second time this motor has been used, so im hoping that it goes into production in some ford vehicle, and if nothing else, a ford racing performance engine...
hope this helps skaala