I guys,

Looks like the Avon could benifit from a rear anti roll bar. Any ideas where I could get one?

Anyone fitted one? How do you fix them on?

Cheers

Are you sure you really need one? The COG is pretty low. If you are running rear wishbones (as opposed to a live axle) and plan on taking it racing, then i could be persuaded it's a good idea.
I think if your spring and shock settings are optimal, then you shouldn't need one in such a car.