A few days ago I thought I was catching a whiff of burning electricals as I was driving but it came and went and, this being a near new Toyota with only 10K miles, I didn't pay it much mind. The other night I opened the door to our garage where I had parked my Toyota Camry Hybrid an hour previous and encountered a room full of foul-smelling, melted plastic type smoke! Thinking my car was having a meltdown I quickly moved it outside, far from our house.
When I checked under the hood I discovered a piece of thick black foam insulation from beneath the front cross bar (above the radiator) had come unglued and came to rest on the exhaust header where it melted in place and apparently smoked when the car got hot. Living on the top of a steep hill this coincided with my return home.
A paint scraper and a rag with acetone cleaned up the header. The loose foam strip was torn off.. seemed useless to begin with.
Burning smell/smoke filled garage
Two climate control systems, one inside and the other at the tailpipe. 
Someone is going to burn a car down and then maybe Toyo will figure out WTH this friggan foam is for. Mine has been gone since the first one failed on Wild Bills car.
