The first thing those guys add are stickers, horsepower losing fart cans, speakers.
You're completely right that the word 'turbo' is a buzzword amoung these people and they are into them.
I think CART should be going after Honda again. 1. Honda already has the engine developed! 2. Honda left because CART jerked them around. Honda was number three in IRL last year. Honda and Toyota were not thrilled that the engine rules were bent to favour GM. In other words 'you are allowed to compete, but don't win.' 3. CART is under new management. 4. I think Honda's target market would be more interested in road/street racing than oval racing. 5. Honda was the best manufacturer CART had in terms of consistently producing competetive engines.
Another possibility is BMW. Obviously they're dumping money into formula BMW. If they want to have the racing presence over here that they have in Europe, they're going to need to be in a top level series. Clearly CART more aptly fits what they try to do with their cars/brand image.