[elhigh]

Definitely pull the deflector. It's adding frontal area PLUS wake turbulence, while giving nothing in return. If you use the sunroof a lot, it may be worth the trouble, but when I had a car with a sunroof, I never ever used it, and it ate up precious headroom.

Driving habits are everything in hypermiling. It's one thing to have the slickest car possible e.g. Basjoos, but even so he's hypermiling a hypermiler car: the average driver couldn't do better than 50mpg with that car, he's easily pulling in much higher numbers due to better habits.

Hypermiling is a totally different kind of performance driving. The results are a bit less sexy than loud noises and high speed, but 20 years later your car will stilll be in running condition and you'll have burned thousands fewer dollars in fuel.