I have the same smell. I investigated, and found a slight leak from one of the spark plug tubes. It is not enough to drip when parked, but you can see a trail showing the leak dripping onto the exhaust, right around the O2 sensor.
From what I understand, it is a common issue, but an easy fix (O-ring replacement)
It is a little embarrassing to park next to a friend, with a stinky, slightly smoky car
