SC400TT

iTrader: (4)

This one is to Devildog, if you're out there. Of course, anyone else with a comment is certainly welcome to speak up. I am quite new to the forum. I have a 93 Lexus SC400 with 92,000 miles. It is running well, but there is this annoying noise which I and Lexuscannot seem to clearly diagnose. The sound can only be heard when my windows are rolled up, and I am cruising between 20 and 30 mph. The sound seems to be coming from behind the area between the gearshift ****, and the center AC vent. It sounds like I clipped a clothes pin to the spoke of a bicycle and attached a playing card to it so that it would make this noise as the playing card strikes each spoke. The noise speeds up and slows down as the car does. I have a difficult time re-creating the noise when accelerating.

Any ideas? There is some thought that this is being caused by the drive shaft. Expensive to replace, if so.