$1500 additions to a Mustang V6

I would go with a Diablo Predator programmer it increases the timing and increases horse power and torque plus it lets you modify other setting for example bigger wheels or new gears. Second modification would be a set of gears 3.73 or 4.10 depending on your transmisson type also a posi-trac it's best to do both at the same time. both of those items are fairly expensive the programmer is about $400.00 the gears are fairly inexpensive the bulk of the cost for them are installation. Other Options you have is replace the cat-back exhaust go with something 2.25 inches in diamater and replace the stock Y pipe with a X pipe **NOTE** if your planning a power adder like turbo or a supercharger then your pipe diamater needs to be bigger. It all depends on your goal if you want cheap power then a Nitro kit would do the trick. but if you wanna build up your stang to be a power house on the v6 powerplant then your options are in addition to the one's i listed above is a stroker kit/powerpak from Super Six Motorsports and then adding a Vortech/Procharger also changing the rear end to a 8.8" from a GT or above would support the extra power your putting to the ground suspension upgrades pan hard bars to keep the power from the rear wheels to the ground. anyway those are my two cents most of the others guys on here are very knowledgable.

you could get an xcal2 from vmptuning.com. it would come with three custom tunes based on what you have and are goin to do. i would get exhaust, (2.25" or 2.5" pipes), a cai, some springs to get a good stance and better handling, and gears/t-lok. then think about getting the tuner. it works better the more mods you have. what year is your car? if you do gears you might need to get a chip to fix your speedometer and odometer. if its a 5 speed get a new shifter, auto think about a shift kit. an auto also benefits a LOT more than a 5 speed with a tuner, especially in the beginning.