Stealth, thanks
Many a year ago when I was OCD about cleaning my car, I used to go away with friends and excitingish cars to France, I'd get up early every morning and fully valet my car and wax ready for the thrash.....
I found clay superb, then brought some maguiars and it wasn't a patch on Zymol 'blutack'
My polish kit way back then was. Autoglym wash, Zymol clay, Zymol HDcleanse, Zymol carbon wax (I also had a couple of small tubs of the more exotic, but found the carbon very good and easy) The trouble is I have no space any more to polish my car at home, so I tend to go to the £6 hands free (Sorry, yes I know...)
When I had a black M5 and as really busy I used some really aggressive car cleaner (he bought a 2 gallon drum) spray on leave 15 mins then get off quick, it did an amazing job ! Don't know what it was or how much damage it might do if used regularly but it was remarkable, like putting a stained teacup in a dishwasher on the soiled pan cycle