Been there done this! One cold morning I started my pickup and bits of toilet paper came blowing out the vents. The little joker had gotten into my emergency roll and built a toilet paper nest in the heater. Being more agile in those days I tore the dash out and vacuumed everything. I had to buy some small flexible tubing to tape to the vacuum hose to get to some spots in the duct work. While I had it apart, I made some screens for the fresh air ducts, seemed to work because I didn't have any more problems with that old truck. When the same thing happened to my wife's Grand Am, I sold it. But I was looking for a reason to get rid of that piece of crap anyway.
