Attented a trackday today with a lot of cars out at the same time, and I had constant troubles with the buffer filling up on the d700. I'm using sandisk extreme III cards (30mb/sec speed) and shooting 14 bit nef files.

Has anyone got any experience with faster cards or anything else that might help? I've read about people getting their D3 buffer upgraded, is something like this available for the D700? Or is the D3s my only hope?