Something to add - Common sense.
If somebody comes out of nowhere and is chewing on your bumper, just let them go. Forsake your pride and let the guys who know what they're doing go out in front.
Also our Z's arent "slow" by any means so certain cars you do need to lift for. Just because you're faster in a straight doesn't mean your faster 90% of the rest of the track.
Common courtesy at track days is a must, at least if you intend on making some friends and not getting chewed out after you get off track.. OH and dont go in a run group youre not fast enough for. Just because youve got 3 track days doesnt mean youre ready for intermediate.