If you used 30% of the colly in one coat, you've used way too much! The thinner the coat the better, apply with a sponge applicator, allow to cure and then buff off with a nice soft fluffy microfibre cloth. Apply another layer, 24 hrs later if you can. A cotton cloth like a shirt will scratch like mad as fine particles of dirt have nowhere to go other than scratch across the surface of the paint.
When the bug hits you hard, you'll be buying a polisher, crying at the site of every micro scratch and suffering from OCD. Half way through polishing the rear quarter panel -
And the final result -
Clayed with BH Clay
Polished with Gtechniq P1 by DAS-6
Glazed with Clearkote Yellow Moose Wax
Two Coats of Chemical Guys Blacklight Hybrid Finish
Wiped down with Chemical Guys V7 Sealant