What is the best tuner(programmer)? I have a 05 v6 with auto. I want the tranny to shift good but hard when I run it hard. My tires are shorter then stock so I need to change the speedo. As far as power I want the most I can without killing mileage. I would have thought by now we could have a programmer that was able to use on more then one car. I do have a 100.000 mile warranty so if I do have to go in for work I am sure I would have to set it back to stock or lose warranty. Has anyone used more then one and what would be the best?