Sounds like we have a heat shield rattle (typical thin metal ringing noise) going on somewhere in the front half of the vehicle - can't tell if its on/near the engine, or the exhaust system. I'm going to get the car on a lift to do the trans fluid here soon (hopefully), so I'm going to have a look and see.
I swear I smell something different, as well, and I only noticed it when I noticed the rattle.
Anyone have any ideas what it might be, so I can focus my initial search on that area when we have the car up?
I believe I have the same rattle on start up/acceleration. In park/neutral at about 1800rpm you can get it to resonate. Have to crawl under. My dealer said it was brake dust shield or something related.
I've actually been quite impressed that my Cruze, despite it's diesel engine, is far more solid than my other cars. My 2004 Impala had heat shield rattle, and my 2009 Subaru Outback has the most horrible heat shield rattle I've ever heard (common for those cars, just Google it).
At nearly 60,000 miles (only about 15k behind my Outback), my Cruze is mostly solid with only minor interior rattles which I blame on the horribly pitted roads around Oregon from all the studded tires.
It's the little stuff that gets it... Mine's going in for a long trip to the dealer soonish.
The serpentine belt and tensioner are getting replaced, under warranty.
The dash is going to come apart so they can fix the insturment cluster rattle, under warranty.
annnd some odd piece I found on the floor is going to be put back where it's suppose to, under warranty.