I think the best part would be the lack of noise (other than tire noise) as you cruise through the trees (other traffic and buses notwithstanding).
The Tesla Roadster is not terribly noisy, but it's not nearly as quiet as the Prius in electric mode. That built-in liquid-cooling plant for the batteries is noisy enough to be annoying. I had been expecting total quiet (when I was given a ride in a prototype a couple of years ago while visiting their HQ) and was disappointed. But I'd still have bought one had they actually been available.
