[pinnacle]

My wife has a 2008 Sienna LX we bought last Labor Day. Lately, she says the interior smells when she uses the heat. She says it smells like a wet dog. It's pretty cold in Michigan so I am wondering if an animal crawled up into her engine compartment to get warm and then died. She does not notice the smell outside the Sienna and she only notices it inside after she has been running the heat. Where should I start to look? Thanks.