Like others have said, I think when manufacturers start pushing electric ready kits out, large electric cars will grow in popularity. Same thing happened in the E-heli scene. About 2 years ago the only way to get an electric heli larger than 500mm was to spend thousands on a custom kit, or to convert a nitro powered Raptor, Hawk, etc. The conversion scene was similar to here, only conversions were easier due to a few people making conversion kits. But when Century released their Swift at a killer price, Mikado dropped the price of their Logo helis (both electric out the box). Then came Align with their Trex600, and the Raptor E550. At the same time Lipo and motor prices have dropped considerably. There are now no less than 5 very well priced out of the box large electric helis all competing with each other. It's never been easier and cheaper to get a big electric heli. Well electric gear is pretty cheap now so it's really upto car manufacturers to start pushing electric kits.

I think people don't realise that although nitro might be easier and cheaper to get going initially, it's arguably more expensive and more maintenance prone in the long run. Electric is a bliss in comparison!