I'm kind of a fast driver as well. Of course that depends on the traffic, weather, time of day, how I feel and the tune on the radio, but most times, I have a hard time minding the speedlimits. Luckily our car can't do faster than 200 (170 is still fine, after that it gets kinda hard to keep it on the road).
At daytime, I usually drive about 20kph too fast. At night, I don't care (esp on highways) and I do whatever I like. In the 6 years I've been driving, I got fined twice for doing 10kph over the limit.
I also drive a lot in Germany... many of the German highways don't have real speedlimits. So that's kind of freeplay to me (160/170kph).
Oh btw... my gf sometimes drives like she's insane... she really doesn't give a damn about speedlimits. She still hasn't been caught once (in the 2 years she's had her license).