I like ase2dais' advice in the context for beginners. Almost every rule for beginners gets turned on its head for advanced autocrossers, but those are lessons to be learned later.
I will say that some people don't "get it" about speed and drive way too slowly, not realizing the potential of their cars, particularly cars like the M3. Even at their very first event I've seen people pick up 3-seconds or more after riding with an experienced driver.
I should say that for every driver that is way too slow for their cars, there are probably five or ten that drive way too fast for their cars. For these, following the guidelines will result in speed more quickly than persisting in driving too aggressively.