Today I changed some of the transmission oil in my 2005 XKR. At 82K miles I feel that it's the right think to do. The dealer wanted to charge me $1,250.00 to completely flush and refill. Another Jaguar specialist wanted $850.00 for the same procedure. I did a bit of research and read that transmission fluid attracts water (just like the brake fluid) and over time, there may be water running through the gears. Whether this is true or not, I don't know, but certainly did not want to take chances. I bought 6 bottles of oil at the dealer at $50.00 per bottle (1 Liter in a bottle) (It's cheaper to pour Grey Goose Vodka in there) and had a transmission shop do the procedure. It only took them an hour from start to finish and they used only 4 bottles of fluid. Now the car shifts super smooth and I feel confident that this will last me for at least 3 years.