My car only does this while it's cold out (-20 in Canada, -4 in the US) and while I warm up my car as much as I can, it still makes a howling sound.

It speeds up as I speed up, so It has to be the drive train, but wondering if it could be that transmission problem people are having.

04.5 touring, 36k miles.

 

Mine kinda does the same, but I thought it was my soft top.

 

I was wondering the same thing the other day. I wouldn't freak out about it though. Every car I've ever had has done it.

 

Mine has done this since I bought the car. It goes away once car warms up. Still have no clue what it is.

 

Cold weather = denser air = moah powa = moar HOWLING! :-)

 

My 2007 Base does the same thing, well makes a howling noise when its cold. Thought it was just the rear diff. getting lubed up which would explain why it goes away after driving a little bit.