Dough, hit it with a claybar & TAKE YOUR TIME. LIGHTLY over it with LOTS of soapy water. Then hit it with your P21 (that's what you said you used right?) Then go over it with a good wax (P21s or Blitz) If the clay doesn't get it after a couple of times it's going to take a buffer and one of 3Ms buffing compounds & a buffer. You might try calling Car Care Specialties @ 1.877.796.8300 for some answers. (there's a guy there who's a chemical engineer and he's sharp as a tack - kind of obnoxious but good info and he won't do you wrong)