SAE papers?
 

I'm seeing referrence to SAE papers, and when I went to check, I found out that there's a steep charge for them.

What papers do people here have? I'm interested in reading papers regarding the reduction of both lift and drag.

1999-01-0651 would be a good one for people here to read:
The Influence of Aerodynamic Lift on High-Speed Stability

Abstract:
The effect of aerodynamic lift on both straight-line stability and lane-change maneuverability of several small- and medium-sized European passenger cars has been determined from subjective track tests. The straight-line and maneuvering performance degrades with increasing lift and decreasing pitching moment. Increasing speed exacerbates the problem.

...SAE papers are typically not free, unless the original author makes them available to the public.

Sae
 

or you could just make the leap to Hucho's book which will have all that and then some.