Advice on hood cleaning/waterproofing

[duncs]

Couldn't help but notice that the outside of the roof on my scruffy old S1 has turned from dark blue to a sort of slimy green colour. Closer inspection revealed that it has indeed been colonised by some sort of vegetative life form. I've given it a scrubbing with a soft nail brush and some car shampoo and it's come up much better, but still not completeley cleared.
Does anyone have any tips on how to get it completely clean (I wondered about that foaming upholstery cleaner that works wonders on seats?) and once clean do I need to put on some sort of waterproofing (like Fabsil??).
Any advice/experience gratefully received.
Thanks,
Duncan.

[duncs]

Thanks but what about the remaining green tinge? I don't want to seal it in with the fabsil, I'd rather get it out first. Might try the foaming cleaner tomorrow.
Watch this space!

[duncs]

Thanks for that Becky, I've had a look at the Renovo website and it answers all my questions. I think I'll go for the full kit with cleaner etc for £45.