I've detailed about 10 full cars at this stage. I have much better technique and products at my disposal now compared to the first few cars I've done.
The clay was taking some serious crap off the paint when I started.However, now I use a strong shampoo, tar remover and a full decontamination with Dragons Breath from valet pro prior to clay barring. Almost nothing shows up on the clay bar now...
You will of course be shunned by the googlers if you don't still clay bar it though .