Thanks guys, that pretty much answers it. As an aside, I bought 20 litres of the stuff (4 x 5 bottle for less than £20 plus £6 p&p and it was delivered in 2 days.
obviously haven't tried it yet but they have excellent feedback.
Ebay link:
http://stores.shop.ebay.co.uk/CarChe...__W0QQ_armrsZ1