I use this as a pre-clean diluted into another spray bottle :
http://www.cleanyourcar.co.uk/detail.../prod_737.html
Because it dilutes 500ml lasts forever.
Then for a 2nd pass I use :
http://www.cleanyourcar.co.uk/index....&productId=662
Although at the moment I use meguiars as Halfords had a deal 3 for 2.