Very much true in OC and L.A. Also, a lot of Honda-ricers tone down on their "street racing" ever since a couple really bad & deadly accidents around the area for the past 2 years.

The only ones that seems scarily aggressive on the road nowadays are Truck/SUV/Van drivers. I auto-x a ford150 and the stopping distance (even with aftermarket pro-am brakes) is still very long. I can't imagine why anyone in a 4000lb car would want to tailgate my Z. I usually do the following:

1) lightly tap my brakes to move him away.
2) Change lanes
3) If he continues, I put on my emergency blinker, count to 3, and then pull a really hard stop.