Clutch or cabin filter extra dirty.

 

Maybe its the trash can by your car

 

Or you might also want to check in front of your radiator for dead animals like birds. I sucked in a bird once and it sucked removing its maggot infested body. On that note I ran over a mouse today which was not cool. Found it's smashed body stuck to my rear bumper.

 

All joking aside I have noticed the same type of smell on my 07 and it is the strongest in the trunk. Could it be some type of sealent or oil used for the top?