Hi. I don't think you need to sell the idea of living in a step van on the open road.
However, I do question the efficacy of your plan. Are you going to leave in place the de-tuned motor
you already own when you replace it with an motor/generator expensive enough to have equal output? Plus a second electric unit?
How about this? From a 2009 Ecomodder thread:
http://ecomodder.com/forum/showthrea...tml#post124993
I'd never seen this 2009 thread before—I found it through Google Image Search. It came up first! It's an electric motor that inlines behind the transmission, like an overdrive. You'll want one that does regeneration. Then add a modest battery pack scavenged from a Leaf or something, add MPaulHolmes open-source controller and you'd have a KERS (Kinetic Energy Recovery System).
More here:
https://www.google.com/search?q=inli...electric+motor
You have two posts so you're past the Introductions subforum stage. As soon as you have five posts you can post pictures.
I see you have a presence on the Drive On Wood! forum but I haven't looked at your posts there. Isn't there a lot of cleaning filters involved?
You can probably get to 10mpg on aerodynamics alone. There's a subforum for that.