The Leaf and the Tesla Roadster are series production vehicles, produced in quantities of several thousand. Only the converted AE86 was not, though at least its mechanical bits were series production quality.
You just can't compare series production to one-off race. Look at Nobuhiro "Monster" Tajima's motor failure at Pikes Peak. Huge budgets and significant schedule pressure do not guarantee reliability.
All four production Zeros have been dead reliable, all season long. They're also very slow.
The Empulse RR was very reliable in races last year, and fairly reliable in races this year. SNAFU at Infineon, and Eric and Steve's bikes have been taking turns with performance glitches in qualifying (LS and Miller, Steve) and race (LS, Eric). Maybe the reliability last year was due to not racing in 2010.
Either way.. you can basically have very reliable last year's performance or mostly reliable this year's performance. EV performance is advancing so quickly that if you want to stay at the top, you have to accept the risks.