I've noticed a grinding noise on my 05 XJR on downshift from 6th down to 5th or 5th to 4th from anywhere between 40-50mph. I originally thought it was the "squawk" noise that was referenced in the Technical Service Bulletin and the dealer put the additive into the transmission. The only other anomaly is that I get the DSC unavailable warning intermittently as well. Could be connected...probably not. Anybody else familiar with this problem?