a guide I found

http://www.detailedimage.com/Auto-De...uide/Clay-Bar/

I used the meguires claybar kit, we only did a bonnet and wings as it was a first go, but you could feel and see the difference, also polishing after brought better results will less effort. There wasn't an instant JESUS it gleaming straight after the baring, but there was noticably less swirl marks and you fingers slid across the paintwork, with more work it could have been got even better and it was after polishing that you could appreciate how much better the finish was.

Was easy to use and after a few seconds you get to know how much prressure to use, and can feel the resistance lessen as the surface becomes smoother and less full of shite. Plus you will be amazed at what you would think would be a clean car how much shit is on the claybar afterwards.

One thing worth noting was to soften the bar up in warm water as in cold weather it will be firmer and could cause damage if hard. Also, get the car as clean as possible first so that there is less unnesasery crap being collected by the bar.

Would think to do it properly and polish it up after you looking at a good days work.