Soapy water and a stiff brush.

To stop the problem in the future, try one of these or something similar.
http://www.miatamania.com/Shop/ViewP...eIndexID=52509

Back in the days when I had a ragtop (Fiat), I was recommended cleaning products from BMW... supposed to be very good for all sorts of things.. never used them, but might be worth enquiring

Martin

I blame Jools for all of this!

Chop the trees down !

Jools, the BMW kit for this is very good apparently,I think theirs is actually made by Revox ? and just branded, I will do some digging and advise further

Thanks guys. The trees are in a conservation area with preservation orders on them. I could take a chainsaw to them but it would cost me loads in fines.

I've tried the soapy water and scrubbing brush without much joy, perhaps because the owners manual specifically states "Never use a scrubbing brush on the roof" so I didn't exactly attack it - perhaps I was too gentle.

I'll see what BMW do