More Dual Advice..

Catback is good for now.....I prefer Magnaflow over any other.

flowmaster ...sorry to those that have them they sound and perform like crap.

out of the choices you gave though I would go with Borla, then Mac, then the flows.

I like the dynomax superturbos. The car stays fairly quiet, but you still get some good rumble in the cabin.

GT take-offs sound really good to me and are relativly cheap.

I had 40 series Flow's on my V6 with MAC shorty headers and a custom off-road x-pipe and i thought they sounded great. Best sounding V6 in the area actually. Now though, that I've gotten my MACh1, I installed Borla Stingers with just a cat-back system and I was THOROUGHLY impressed. Personally, I really think you should look into those and invest in a great exhaust system.

Just my two cents.

if your going to start modding your 3.8 then just start with a good exhaust that you won`t have to upgrade in the future to handle more hp. the factory y pipes are extremely restrictive and it is better to replace them instead of going with a catback system designed to bolt to the 3.8`s y-pipe

i Reccomend MAC exhaust the MAC h-pipes will bolt right to your factory headers. here are part numbers

MAC catalytic h-pipe part#C38200 $399.50
MAC offroad h-pipe part#34020 $169.50

the correct cat back that will bolt to the h-pipes is

MAC 98-03 4.6l v8 catback part# TK2298 $299.50

i know the catback is designed for the 4.6 but MAC V6 h-pipes are designed to be used with their v8 catbacks.

the only other things you will need is a muffler hanger bracket and tailpipe hanger from the same year as yours 4.6

you will have to hang the tailpipes lower to clear your rear bumper or order a v8 rear bumper from www.stangparts.com for $125.00
go to their product inventory then go to bumpers section
they also sell a dual exhaust conversion using GT takeoffs and an adapter to the v6 exhaust and v8 rear bumper for $369.00 also in the bumpers section

if you are tight on money and major mods are not going to be added the dual conversion from stangparts is the way i`d go. but if more mods are on the menu then do yourself a favor and just go with the MAC system. it will add more power to your 6 than any catback designed to bolt to the factory Y-pipe

i hope this helps