[ennored]

At 55 MPH, you're definitely going to have to attack more than just aero. And I doubt the small bits of aero stuff will be worth it. Since it's a one time deal, how about 4 mini spares to lower the rolling resistance. Should be nearly free and maybe net some decent gains?

I'd plug some numbers in to the Aerodynamic & rolling resistance, power & MPG calculator here at Ecomodder. It'll show you just where the power is going rolling down the road at 55 MPH.