Yeah I think I read on the detailing forum that it comes from the plastics in the car curing or something. I've cleaned mine several times in the past 2 months since I bought it, I use invisible glass and it comes right off.
Yup that is how mine is now. I need to not be lazy and clean it. I just did not know if this was normal. I guess I can imagine it being worse in high humid places. But not here.