All i got is a cobb sri amd test pipe, i will be changing spark plugs very soon along with catback exhaust (but i dont think this affects much)
I would consider purchasing fuel pump internals and a way to monitor (forgot to mention you can monitor with an AP and take datalogs which are very beneficial to monitoring multiple things at once until you upload it to a computer). The internals don't add power but because you've modified your exhaust with a test pipe, their have been cases of fuel pressure dropping to low and people hitting fuel cut. The new internals prevent that by increasing fuel pressure a few hundred psi. However thats not always the case, but its just something to be aware of.
The stock catback isn't really much of a restriction and won't net you any power gains, but if you want louder sound it may be cheaper to just have someone weld in bigger mufflers.
Personally when I first bought my car, I wanted to get all the ducks out of the pond so my purchases in order after studying were RMM/F+R Diff mounts>more reading>Intake>more reading>AP>Internals>more reading>DP
Of course a short shifter and some exterior mods were thrown in there as well
Liquid Platinum 07 Speed 6
JBR 80duro RMM, 70 duro TMM/PMM, Sure Juggernaut, Sure Dreadnaught
GTX3071, Cobb AP, HTP3.5" Intake, Streetunit TMIC, M2 DP, TurboSmart BOV, Grimmspeed EBCS, AT Internals, GP Werks BSD & Baffle, Denso ITV22, TWM Stage 2, Dashhawk, JBR OCC, JBR TB TIG, SURE IM TIG, VTCS Delete, Ford Transit Oil Filter Conversion, Clean Valves!
LED tail lights, 20% tint, EVO X rims and VG Sharkfin
Big Turbo baby!
Soon to install CPE Exh. Mani