I've noticed the smell as well. 05' Autostick Convertible. Funny thing is, I've never noticed the smell until after I hit 4k miles (now a shade short of 5k miles). I've been standing on the gas pretty hard lately, so I'm hoping it's the cats burning off.

Another thing I've noticed is the sound is slowly starting to change. Sounding more throaty. Is that what happens when the cats burn off?

If I remember correctly, old "cherry bombs" did the same thing.