Originally Posted by verbs
From experience in AZ, don't go with Dinan for a few reasons.
1. There are only 2 authorized Dinan dealers in AZ, both in Phoenix.....and they're both not great. The dealer in Scottsdale is run by a lying crook.
2. When BMW does a software update to your car you'll have to drag your butt back to a Dinan dealer to get your car reflashed if the update erases the tune. I had to drop my car off for at least half a day to a day probably 4 times a year. Very annoying.
3. You pay a huge premium for Dinan which isn't worth it anymore because you don't get the benefit in Arizona of having your car's powertrain be warranty-able directly by BMW, and I have read of instances where both Dinan and BMW refused to warranty someone's car problems and both played the blame game.
4. Due to #2 and #3, I would wait and get a tune that comes on a handheld device that plugs into your car like the one ESS Tuning has for the E90 series cars. You'll get better performance gains, pay half as much, and won't have to go out of your way to get your car reflashed at a Dinan center multiple times per year.
Just because Dinan is not a good option for you because of your location does not mean Dinan is a bad choice. Dinan is an excellent choice if you want the piece of mind that your car is still protected by a warranty.
BMW does not update the car software as often as you suggest. They rarely do it once a year....