Re: Which Flash Tuner is best
To the best of my knowledge, there is no tuner that can tune multiple cars. The tuner is used for the car it is "locked" to. Once you use the tuner on a vehicle, the tuner downloads the stock programming, and uploads the custom tune to the PCM module, and it is locked to that vehicle electronically.
I personally use the SCT tuning device. (Specifically the SCT II XCalibrator) SCT also seems to be the most popular, most used.
I also do not recommend writing a tune or changing some stock parameters if you are not experienced in it. You can unwittingly do alot of damage to your car. Its best to leave it to the pros, such as Brenspeed, Bamachips, and JDM Engineering, to name a few. Also, on your 08 GT, to take full advantage of a custom tune it is a good idea to look into a cold air intake (aka "CAI") as well as a tuner. They can be usually found as a package, and work in conjunction with each other. Hope this info. helps!