At what problem can you guys attribute a lot of vibration inside the cabin of the Z at high speed. The vibration is to a level that the dash panel also vibrates and makes noises on a bad way. I checked an put air on the tires and also got the car aligned but the improvement was very minimum. The rear suspension still very sloppy . I just want some advice on what might be the reason for this deterioration in handling on my Z. This are the number the alignment shop was able to get on my Z,

Front Camber: -1.2 degrees (Left) and -1.2 degrees (Right)
Front Toe: .08 degrees (Left) and .06 degrees (Right)

Rear Camber: -1.9 degrees (Left) and -2.0 degrees (Right)
Rear Toe: .11 degrees (Left) and .11 degrees (Ri

 

Have each tire/wheel radial force balanced on a GSP9700 machine you will be surprised at how inferior the typical balancers are.

http://www.gsp9700.com/pub/technical/4127T/4127t.cfm

 

+1, the shop I take my wheels to, use this. My car tracks well, and I have gained more mileage per set.

 

Vibration could also be caused by a damaged driveshaft or driveline.

 

^+1
there's a lot of things that can be attributed to vibrations, not just camber