What can be done with my e32?

[Hogwit]

I have a Citicar (all electric vehicle from the 70's) and I love it, but as most ev drivers know, you need a backup, gas powered, car for long trips. My backup is pretty much the opposite of a "green" car being that it is massive, weighs about 4300 pounds and has a 5.0 liter V12 sitting under the hood. So what SIMPLE and/or CHEAP mods can be done to it to improve gas mileage.
Please don't tell me things such as:
Onboard hydrogen generation (don't believe it)
CNG conversion (Up front cost is too high...I'm only 16 years old)
All electric conversion
Engine swap
Radical body changes such as boat tails, chop top, etc
Radical weight reduction via deletion of sound deadoning, passenger seats, or others

As stated previously, these things have to be CHEAP; in my definition that is, it has to pay for itself within a year (7,500 miles or less).

[UltArc]

65+ Vehicle modifications for better fuel economy - EcoModder.com

100+ Hypermiling / ecodriving tips & tactics for better mpg - EcoModder.com

Tire pressure, followed by grille block

-While Rethinking Driving-

Then - Underbody, rear wheel wells, pizza pans, other more drastic/involved things.