Peter - it might be me coming from an age of duco paint and "cut and polishing", or it might be that the Antipodes are still a long way from England, but I've not come across this "claying" concept until I joined this BB. My car arrived from England with lots of tiny hard spots on the paint that you cannot see, only feel, that I assume is hardened tar. I used a razor to remove them from the glass on the rear side windows (ZT-T), but haven't even tried on the paint.
Will claying do the job, and what exactly is it, please?