hey i have a 04 3.9L v6 mustang auto, and i was wondering if anyone knew where i could get a auto shift kit for my car

 

3.9L??? you're crazy.
I think precision industries (sponsor here) would have one. they have stalls and stuff like that.

 

Get a tuner and make the tuner become your shift kit thats what 03yellowpony and I did.

 

04s with both the 3.8 and 3.9 have a diffenet computer, so a diablo for a 03 mustang will not work for an 04, someone else may have one but im goin to bed and ill google for one in the morning, (its 10 here buy when you get up at three, its a long day)

 

SCT makes a tuner for BOTH the 04 3.8 and 3.9.

 

looks like SCT is the only one, no diablo and no hypertech
http://www.sctflash.com/car_chart.php

 

how exactly does a tuner work? does it just reprogram my car to shift at a better rate? (sorry kinda new to this stuff)

 

The tuner is used to reprogram the ECM. You can change a lot of parameters. Not just the tranny programming. You can use it to turn off the speed limiter, reprogram shift pressure(kind of like adding a shift kit), shift points, rev limiter, air/fuel ratio, speedo cal for when you add gears, and a lot more. The thing about the SCT is, they put in 3 custom tunes based on what YOU want it to do. You cna create whatever tune you want also. It's called a custom tune. And they are pretty easy to use. You plug it into the OBDll port under the dash, and answer a few questions, and VOILLA! DONE!

EDIT................
Hehehehe..BEAT YA TO IT!

 

you adjust shift points, and firmness, so you can have your car shift at 6k at WOT and harder as long as you reset the limiters, you can adjust for gears and larger tires, it will also tune to run premium fuel etc.

 

I have a trans go shift kit and a chip. Save your money and just get a programmer. The only reason I did the shift kit as well as the chip is because I also changed my torque converter, so I figured I'd do it all at once.