So I'm about to be in possession of a new (to me) 2010 Prius Gen III and I will be on a mission to make this the most fuel efficient Prius in the known universe . Having said that, I will definitely be starting off with the Enginer PHEV kit (probably 4kwh)...but indirectly, I am looking to weight savings to help compliment the plug-in advantage... Having said that...I have a couple of rules. I am not sacrificing vehicle aesthetics or common comfort features (so no ripping out seats, headrests, interior panels, etc...I've seen the posts on these crazies ) . Also, I am not compromising the structural integrity of the vehicle (so no cutting holes in the frame, body, etc.) So far, this is the plan... Wheels - Going to go with the Volk/Rays TE37's 15x6.5...at 4.02oz (8.86lbs) these seem to be the lightest wheels available. Yes, they're expensive...and yes, 15's look like crap on these cars...but again, the objective is efficiency here, and I'm on a grant so I have no problem spending someone elses money . I will also invest in either forged aluminum or Ti lug nuts to squeeze off an extra .5 lb per corner. Suspension - Going to drop it with either TEIN or Tanabe to reduce underbody wind resistance. Body - Definitely going to shave door handles and everything else I can to reduce CDF further. May go with a MINIMAL body kit (front lip and skirts) if the improvement in aerodynamics outweighs the additional weight...I have yet to research in great detail on this subject. Question to all of you who are much more experienced than I in the Prius realm is...what else can be done? I am thinking about replacing all (or at least as much as possible) of the hardware throughout the vehicle with Ti to help, but I am not sure how much that will gain. Open and eager to hear your other ideas... Note: Again, I realize there are plenty of cost efficiency arguments about many of the things that can be done, but lets just say for all intents and purposes that I have been blessed with a proverbial 'blank check' for this project, so I dont need any CPA's advising that I would be better to invest my money in real estate (no offense to all of the moneysmart people out there...I think the same way with my PERSONAL capital). Thanks in advance!