My parents bought a brand new VW Jetta, and it is a nice car...Except we were driving and everyone seemed to be either tailgating us or passing us, and were like WTF!? So I did some looking online and read that many other VW owners were experiencing the same problem. At 55 on the speedo, they were actually going 51-52. It is built into the electronics of the vehicle, I have taken the car past those radar signs at various speeds and the faster you go, the happier it gets. Sub-25mph its almost dead on, but after that it starts reading happier and happier. VW put out documents stating that it is built into the vehicle, and that the odometer and mileage readings are still correct, it knows how far you go, and actually how fast you go, it just lies to you. I have taken the same route in the car as I have in my Jeep, and Dakota, and the trip meters all read the same, but the speedometer is fast on the Jetta. I believe there might be some import laws that mandate the speedometers have to be fast. I dont know why, its annoying, and can be dangerous - tailgaters. Anyways I believe the same thing may be implimented in the FZ-6. Here is some links to a VW forum where they talk about it:
http://forums.tdiclub.com/showthread.php?t=147971
http://forums.tdiclub.com/showthread.php?t=144303
Anyways, enough about cars, I agree that it is very annoying. I try to be a responsible rider most of the time and go the speed limit on my speedo, but then I get cars tailgating me, and they're probably like "That damn motorcycle rider is a dumbass! Isnt he supposed to be speeding, hes on a damn motorcycle!"...Oh well....What can we do