Sorry for the looooooooooong delay in replying, forgot about this thread
Tomis - Yes, the riders where coming out of a corner at about 110 mph and yes I did pan with the riders, used shutter priority mode for 1/25th of a second, I think. I had the zoom out full, 432mm equivalent and ISO at 200, hence some of the noise.
I've started getting into wedding photography a lot now, so am in need of a camera that can handle higher ISOs than the FZ8, which shows noise at 200 or above.
Looking at the Nikon D80 towards the end of the year, but being 16, it takes a loooooooong time to save up for things like that.