I posted (http://www.914world.com/bbs2/index.php?showtopic=304863&st=0) about my car dying on the freeway. Thanks to all who helped. I've converted the advice into a flow chart I hope to be able to use to diagnose future issues. Please let me know if it's correct/missing anything/useful/etc.
Special thanks to Spoke!
It's only for 4-cylinder cars.