I had this fitted as part of the purchase (2nd hand 02 RSC), it just surges to full power, then drops off to no accel, so the car's constantly accelerating and decel, the speed changes by about 5km/h. I took it back this mornign to get adjusted, am yet to gtry it again...hopefully all works well.

I noticed in the manual that the factory cruise for this car is connected to the trip computer so that it's possible to set the cruise digitally to a specific speed....I wish I had that installed.