Right, I cracked on today and it took me a little over 5 hours to get the job done. The clay method that I'd never heard of is awesome. Unbelievable that it would take so much junk off my paintwork. Not sure even now what all those thousands of tiny dark dots were, but reckon now they could've been tarmac as a lot of road surfacing has gone on around here for months now. Not a single scratch or mark left from the cleaning!!!
Started with a rigorous wash and wax with a firm sponge, than the painstaking hours of clay block and spray, then a very healthy layer of liquid wax.
It's never looked so good Until it rained this afternoon and my car got sprayed with dirt. The water droplets were rolling off like small ball bearings!
Thanks for the advice.