https://www.facebook.com/SmythPerformance
Smyth performance sells one nice bodykit project in the US and its pretty efficient. This aint super aero but could be. I think the biggest potential is building similar kit than that but it needs to be also fast like that car and look also nice to have a chance in the market.
Basic ecomodder does not care about the looks and calculates only savins so if its pure efficiency ROI needs to be within few years so that will be tough target to meet.
If there is any bit of fun factor so power to weight ratio proper price aint so big selling argument anymore.