I have a '95 GS300 with 123,000 miles. When I start going over 80 and hit any dip I hear a strange noise. At first I thought it was a road irregularity but more and more I am wondering if it is shocks bottoming out and carry the vibration through the frame in this position. Has anyone else encountered this.

9/11
- New information on this noise. The lower plastic shield (under the engine bay) fell off my car yesterday while on the freeway and started dragging, apparently this was the cause of the noise. The previous mechanic who worked on it also forgot to tighten the radiator cap (I found this out the hard way also) apparently he forgot to screw this piece completely in too. Not going back to him. Had to rip it off to keep driving.

Does anyone know where I can get replacement fasteners for this piece. Kind of worried about what else this mechanic forgot now also.