I guess that you never bothered to see the voltage rating on these caps huh?
Small:
http://www.maxwell.com/ultracapacito...mall_cell.html
http://www.powerstor.com/products_supercapacitors.asp
Medium:
http://www.maxwell.com/ultracapacito...arge_cell.html
Large:
http://www.maxwell.com/ultracapacito...s/modules.html
It's a different chemistry than the giant aluminum foil caps. It's more
expensive, too. Another car battery is cheaper but you could get 416F
by putting 6 Maxwell PC2500 caps in series under your seat, if you
really wanted to. I wouldn't want to be in your car during an accident.