Thanks a lot guys. Really apprieciate the help.
I've read Jimmy's guides (bookmarked now, I should have paid attention this summer on that project
), I'll be on the hunt for a 50mm prime lens now. Funny as I have a non-RC mate who I described about what I was trying to shoot and she recomended a prime lens too, shame her equipment is Nikon though or I'd have pinched it once in a while!.
Its taken a while to work out the effects of ISO, aperture and shutter speed in real-world situations, its easy to read on the laptop then try to remember when trackside. It has helped when trying to shoot full-size motorsport too, but the guides for those aren't really applicable to our stuff, especially when indoors.
Do drivers get annoyed with flash on? I try to avoid it where possible.