Stock aluminum drive shaft from my 04 Cobra. No vibration issues when it was installed; I just upgraded to the carbon fiber drive shaft during the group buy. I am willing to deliver to anybody in the DFW metroplex for free. $150 + shipping
Pic: http://img193.imageshack.us/img193/777/driveshaft.jpg
Pic: http://img193.imageshack.us/img193/777/driveshaft.jpg