I've just build up two new Mac Pro units, each with two Phoenix cards inside. It seems like the cards are quite long in comparison to the rather short PCI Express connection, and I'm worried that the cards will shake/vibrate a lot in the truck, eventually causing damage over time. (Macs are vertical/upright in the rack.)

Has anyone had any problems with this? Is it necessary to fabricate some sort of support at the back end of the cards to prevent them from vibrating too much? I would mash some foam in there except I don't want to obstruct the airflow to the graphics card.

Any thoughts?

Thanks.