As for the warranty issue the CAI would have tio be proven as the source of the issue to deny warranty. Secondly you cannot borrow or rent a tuner as it marrys itself to the vehicle and can only be used on another when the current vehicle is returned to stock.

Do I recommend a tuner and CAI for your vehicle? YES you would not believe the difference it makes in your power and throttle response, it will take your high 14 to low 15 second car and turn it into a high 13 second car in the quarter mile as well as improve your shift points (if you have an auto). It will wake up your car.

You can also opt for a gas mileage type tune that will improve your average mileage substantially although I only use that type of tune if I am hitting the highway to travel a long distance, otherwise I want to chew gas! mainly because I am on a track trying to beat the stock GT Mustangs with my NA V6.

...the follow up question would be what is the best..and cost effectiver tuner for my '07 gt ?

Thanks
Grassy

Either a SCT Xcal3 or a Diablo Predator I prefer the Predator but a lot like the XCAL 3. Intakes are many but the C&L, JLT and BBK are some of the more supported ones, on my V6 I use a Demolet Tunable Induction with the Diablo Sport Predator tuner and am now back to the BAMA Chips 91 Octane Race Tune.

You can get a used SCT XCAL 3 for around 250.00 and it would be a good fit for you I think. I had 2 of them for sale but they both are gone now.

when i bought 1 for my audi like 2 years ago i could change a whole hell of alot . it was fun but i got myself in a bit of trubble a few times. but as long as u have acess to the net u can figure just about anyhting out. mine did not add any power just let me change everything from my headlight level to my auto window feature on my key fob. there might have been a way to play with the power but all the engine stuff was way way beond me so i left it alone but i did run the logger from time to time just to see if i could make it work.

I'd suggest going with an sct tuner as 90% of tuner shops out there use sct software. It will give you the most options of shops to get a tune from

One word GARBAGE.