I have a 08 mustang GT with K&N CAI and flowmasters and wondering if the SCT livewire tuner would be a good buy

 

for those 2 mods you dont need a tuner. but if you plan on getting more mods later, a tuner is good idea. i would wait until you get further mods like an o/r midpipe, then order both the midpipe and the tuner at the same time from a place like brenspeed and they'll give you the tune for free. i have the livewire, but i dont use all the things that it can do. unless you are going to mount it to your windshield and view it, i would just get the SCT X3, for tuning purposes it'll work the same.