'93 940 NA wagon.

Just in the last two days (finally window-down driving weather) I noticed that when I'm driving at any speed, there appears to be a (relatively) quiet rubbing noise coming from under the car. Since I can't get out while I'm driving to check exactly where its coming from, I can only guesstimate that it is coming from the front. I'd say it was coming from the driver side, but i'm never a passenger in the car so I can't tell whether it sounds as good from the passenger side.

If I had to describe the the noise, I would say that it almost sounds -- and you have to picture this, its only for reference -- like the noise a rag would make if it were caught on the tire and hit something with every rotation. its not a heavy metallic noise, doesn't sound like metal on metal or rubber on metal. It speeds up and slows down according to my speed. Its pretty quiet, but only compared to the noise the car makes while driving.

I jacked the car up and spun the front tires by hand and didn't hear anything. I didn't do the rear tires yet since it was getting dark, but I figured I'd ask here.

The car drives great. It doesn't pull in any one direction when braking or otherwise. its obviously something that spins in relation to my actual road speed. I didn't hear it speed up when I popped into neutral and revved the engine. All my belts are brand new, 2 days out of the dealer's garage as well.

Any ideas? I'm not worried yet, just confused mainly.