i was told its acid rain or bird crap. also had two spots on my roof that actually started rusting on me from the same stuff. my dealer told me it was not going to be cover 9 times out of ten. only reason i got it painted was because the dealer did not do as they told me they would. i called a complained to Toyota and the next week the truck was in the shop getting painted. 3 days total. mine is also a 06. good luck getting it painted