Might be feasible if you address a broad spectrum... Not sure where in OR you are, but Portland is big on cycling, so potentially lightweight aero velomobile bodies might augment the ecomodding aspect while utilizing a similar skillset as building fiberglass (or other material) aero parts for cars.
As well, a shop that is familiar with EV / hybrid related technology would probably do well.
Trying to targeting the guys that own 15 - 20 year old cars (eg. metro, 5th gen civic, saturn) probably won't get you far as they most likely are pretty tight already and are also willing to do the work themselves (speaking for myself here).
So your target needs to be those that are looser with their money... eg. those that are willing to buy "leading edge" technology (ya, hybrids have been around a while already but they're a lot more leading edge than good 'ol ICE technology) and then want to show their "well off" buddies how much money they can save by converting their HEV to PHEV. This could include making FG/CF aero items for the more popular hybrids (and upcoming all-electric vehicles).
Potentially, you could also pick a good kit car or two, which are relatively aero and lightweight already, and be a builder for it. Offer various electric drive (or even diesel) options and augment the original body with your own "proven" aero improvements...
Regardless, a well done web presence should help you out quite a bit as well...
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