Think about your cell phone. Think about ring tones. Think about the marketplace for ring tones...
There is a ton of money to be made here (well, in the short run).
Then there's all the third-party add-ons (more powerful speakers/transducers or whatnot - most of that is covered by the car audio industry already, though).
I can't wait - I'm sure more than one person will have some awful annoying car "engine" sound - I predict one of the first will be the Jetson's capsule vehicle sound. I imagine another would sound like a playing card in the spokes of a bicycle. Of course, you'll also have the favorite "blown V8" as well as some race car engine sounds. Probably more than a few that sounds like one long faaaaaaarrrrrrrttttt. Oh - of course - make your EV sound like a Harley (likely licensed). Perhaps a VW bug? F1 racecar? Diesel semi? Rocket?
If you wanted to prepare for the market, sampling and recording (professionally) these sounds would be a good place to start. Maybe talk up some of the ideas with respective rights-holders (such as for the Harley sound). Don't forget off-the-wall sounds (what about for braking, acceleration, etc?) - yes, your car can sound like an out of control elephant on a rampage!
Should be an interesting future (and a noisy annoying one, too)...bleh.
