After recommendations from people on this site, I finally bought some Meguiar's. (for my forthcoming mini)
I was at a loose end tonight so decided to give me current car a quick wash (first in months).
Then I thought what the hell I'll try and see if this clay thing is any good.
Oh what a finish!
Used Autoglym car shampoo, rinsed using the Flash Autodry filter. Ok i though the car looks clean and shiney.
Gave the bonnet a once over with the Quik Detailer, the a wee rub with the Quik Clay.
Many thanks for pointing me in the right direction, just need a new car that i can be bothered to keep clean and mega shiney now!