With the fuel cell stacks hidden beneath the floor and the hydrogen tanks and
the ultracapacitor beneath and behind the rear seats, respectively, the
four-passenger cabin is isolated from all hydrogen and high-voltage lines.
Hydrogen gas is colorless and odorless, and it burns almost invisibly. In case
of a leak, therefore, the manufacturer has placed hydrogen sensors throughout
the vehicle to provide warning and automatic gas shut-off. Also, in the event
of a collision, the electrical source power line shuts down.