[graydonengineering]

If you want better mpg, you should re-badge as "Geo Metro" or "Smart for 5. That will get you at least 5 mpg improvement since you wont feel the need to show of "Mustang-like" performance! Most of us use 4mm Chloroplast that goes for $15 to $20 for a 4 x 8' sheet for mods. If you box off the wheel wells and install a belly pan you will significantly cut salt rust damage and reduce drag at the same time! A belly pan take a lot of material so low cost and low weight are critical.