This is a great talk by David Fauth on how to approach Solo Nationals from which course to walk first to how aggressive to be. He picked up autocross tips from his experience as well as from other champions like Bob Tunnell.
David has 5 Solo Nationals Class Championships to go along with 5 Pro Solo Class Championships.
He has autocrossed Dodge Neons, Acura Integra Type R's, BMW 3 series in DSP and FSP and is currently in CM.
I learned a lot from him since he lived and raced here in Denver when I began (even bought my first Integra after talking to him about is - and seeing how fast they could be).
Let us know what you learned and any Solo Nationals Autocross tips you have to share.