Here it is...
LS1GTO.com Forums - GTO Factory paint thickness (we measured)
between 5 and 6 mil thickness. But does that mean just the clear or is that paint and clear? Would you guys consider this thin?
Quote from the post: "Some factory vehicles arrive with as little as 3.5 mils thickness while others may have as much as 7-9 mils or more. Usually vehicles will arrive between 5-6 mil range." You see how inconsistent the paint jobs are? Mine came out extra sucky.
That test was done by tropi-care, a detailing product company who is a sponsor on that forum.