That's pretty interesting. You'd think that it would be fairly bulky for an automotive application, even ignoring the cost. Seems like their original target of trains and off road industrial applications were more appropriate.
If you really think about it, both turbos and superchargers are very well established and proven technologies yet really are not in the automotive market in huge numbers. Aside from turbo-diesels, what percentage of cars do you think run this now? Less than 5% I'd guess.