High speed P&G with good aerodynamics and 55 psi.
I've finally gotten the car to the point where I can P&G (sometimes) on the highway, as long as I work with the hills. There's real potential in increasing the roll-ability of your car. Once you defeat a certain amount of drag and rolling resistance etc., you can P&G and the benefits become even more pronounced.
These mods combined got me here: Full belly pan, low rolling resistance tires at 55 psi (cold), flat wheel covers. The wheel covers were the "last straw".
My 55 mile commute requires driving at fairly normal highway speeds. Until this week that meant little pulse and glide on the highway - speed would just deteriorate too fast in most cases.
Just a word to the wise, hopefully.
Here's a pic of my new wheel cover. Quite flat. Perforated aluminum sheet over a coroplast stiffener, glued together with silicone glue.
There's some detail on the wheel covers and especially the fasteners in this thread:
http://ecomodder.com/forum/showthrea...orn-14306.html