I have a 2005 Crossfire linited with (72,000 miles-automatic transmission) convertible with a transmission issue. As I drive, but not always, as I start out the transmission will not shift as I hit around 4000 RPM's. I then have to stop, turn the car off, start it again, then start out again. Most times it runs fine. But I'd say 1 out of every 5 times I drive it I encounter this problem. Any idea what I'm facing?