my car smells like feet and beef jerky

This weekend we did alot of running around and I am afraid some small animal has crawled up into my car and died!  I has this gross smell  that must have been  festering all night long because when I opened the door this morning, it hit me like a ton of bricks.  Thank god Mike took Noah to school this morning otherwise he might not have survived the stench.

There were 2 coffee cups thanks to my wonderful better half for leaving me his garbage, but that was about it.  They are both from yesterday too and it wasn't that hot out, so I cant possibly imagine it is from spoiled milk.  Plus, I have smelled that smell one too many times thanks to lost baby bottles under the seats and that it not what it is.  I wish I could bottle this disgusting odor and have a science lab tell me what it is, however it might be too gross even for them.

However our friend was in town and one time he left a half eaten Big Mac in our car that we didn't find till a month later so maybe he is the culprit.

I will have to do some investigating tonight and see if I can track down the source.