Dave,
I had the same issue with our Roadster (March 08). I kept topping up and I think this over filled it which caused an over flow that looked like a leak.
Left it alone now and it seems fine, but the header tank level goes up and down a lot each time it's used. So in my experience don't worry if it hits the low level line once in a while.
When it did over flow, it dripped down variuos hoses, engine block etc.
All is OK now, now drips but just a varying level.
Regards
Mark
