One of the primary safety concerns with hybrid and electric cars (aside from thermal runaway of the batteries of course) is the potential for shocks with a high voltage battery on board. Formula One teams are currently developing kinetic energy recovery systems (KERS) which provide hybrid drive capability for introduction in the 2009 season. Most are thought to be working with a flywheel based system but BMW-Sauber at least is rumored to be developing an electric hybrid. Several teams have had incidents with their systems including the Red Bull team that had a fire at their factory. A mechanic for the BMW got a nasty shock when he approached the car as it came into the pits during a recent test session and was knocked to the ground. Safety issues like this are one of the reasons why automakers take so much time in developing production systems. The BMW-Sauber F1 team are not amateurs and have an annual budget in the hundreds of millions of dollars. If you plan on trying any DIY hybrid or electric drive projects make sure you are very careful with the batteries!