Meguiars without a doubt, the 3 step clean, polish and wax is amazing. In fact mine is going in to the garage in a couple of weeks for them to look at a chip on the wing, and I have asked them not to even think about putting a sponge anywhere near it, its taken 3 months to get the paintwork looking like it should have done the day it was delivered, thats thanks to Meguiars, its lifted all the fine scratches out of it.
I dont think the 3 step Meguiars would have removed any scratches as none of the steps contain any abrasive with enough cut . All it would have done is made them less noticeable by filling / masking them.
If you want more info on cleaning or buying car care products try here; http://www.detailingworld.co.uk/
They know everything there is to know about car cleaning.
Zymol car shampoo - its zymol, its the daddy, and you can get it in Halfords for about £8 a bottle
finished off with Harly Wax, a carnauba paste wax, comes in a big round tin, i've had the tit 18 months and have hardly made a dent in the contents - its brilliant to apply and leaves a brilliant finish