Here's some more info:
"But why is lift so bad? You'd be right in assuming that no car produces such a dramatic amount of lift to be dangerous to drive. But lift does negatively affect performance in two ways. First, lift reduces the load acting on the tires. Since the maximum amount of traction available from each tire is a function of the load acting upon it, a reduced load means less available traction.
Lift also causes extra drag called "induced drag," which is a good percentage of the overall drag on the car."
Car Aerodynamics Diagrams - Sport Compact Car Magazine
I didn't join here because I want to squeeze every drop of gas I can. I came here because it seemed like a wealth of information for DIY modifications. My interests lie in eliminating lift and reducing drag at the same time, so when I'm going 70 down the freeway, I know I have all the control I need to avoid accidents, and less drag so I'm paying less at the pump.