First I used a Mothers clay bar on all surfaces. Then I went with step 2 and 3 of the Meguires 3-step. But the spots are still there. I can feel them with my fingernail, but the damn things won't come off. BTW, I tried step 1 in small area densly covered by the white spots and it did nothing. Any suggestions for the next step? Maybe stripping the existing layers of wax off with dishwashing soap?

On a positive note, the clay bar did a great job cleaning the crud off of the rear hatch.

Thanks for all the good replies.