Over the past few years, hybrid cars have gained a few nicknames, but the one that sticks out the most is "The Silent Killer." Since the cars are essentially noise-free when operating under electric power, they pose a threat to pedestrians who don't actually hear the vehicle approaching when they're in situations where the car isn't visible. To address this issue, Lotus has developed "engine sound" software for hybrids, and the results are...interesting.
The software is called the Halosonic Noise Control System and offers several different engine sounds, albeit with mixed results. Presets like the Porsche-style "flat 6" and the "American V8" are at best comparable to original Nintendo caliber reproductions, and would be an effective way to get people to point at you and laugh, if that's what you're into.
But perhaps the spaceship sounds might be more up the average hybrid driver's alley, as they sort of compliment the futuristic vibe hybrids are going for. Either way, these things are total chick magnets, you know?