The car is driven pretty much daily, but it was parked in my driveway for 10 days in November while I was out of the country. Although I don't think it happened then, because the car was at the VW dealership last week and nobody mentioned anything about it then.
And I assumed it was a squirrel because they are everywhere around here. In the past they've snuck into the eaves of our house to steal the fibreglass insulation, and a couple years ago they ripped off all the soft backing from the inside of our barbecue cover.
Anyway, I decided just to pull the rest of the insulation off and leave the underside of the hood bare (apparently it's just sound insulation, and I don't mind hearing a little extra engine noise

). I just hope that when he comes back for another load he doesn't get PO'd and decide to chew on something else instead.
The big question is ,,,where did all that stuff go? I hope it's not all in your vent system. 
If it was a squirrel, they usually stuff their cheeks full of the stuff and carry it back to pimp out their nest. Little bastards probably have a more comfortable bed than I do.
