My upgrades..need more pro help.. How to speed up the v-10 m6!

I purchased a 2007 M6 with 20,000 miles a little over a year ago. I have made a few upgrades to see Power Increases although i am looking for a little more Torque and Edge. My UPGRADES are the

TUBI STYLE EXHAUST(Section3)
K&N AIR INTAKE & FILTER,
EVOSPORT POWER PULLEY KIT,
DINAN STAGE 3 ECU FLASH.

What should i do next...... NEW DIFFERENTIALS OR Replace the K&N INTAKE with a DINAN AIRINTAKE ? I am considering DIFFS, DINAN INTAKE, and even A NITROUS KIT. HAS ANYONE EVER DONE A NITROUS SHOT TO AN M6???? I also need ideas to know how to drop some weight on the vehichle? A New Brake kit, suspension kit some exterior work is in the works, looking for some ideas......

lol what are you trying to beat that you can't already

Its Embarrasing to say got smoked by a New all Hooked up Subaru Wrx Sti turbo. Guy beat me First time we Ran i was in a third gear rolling start not second. Then the next time we ran i burned him had him chasing me at 150 he still couldnt catch up but by then had to slow down.. i can max out at 205 I just need more off the line speed to not get behind from the door. Think the Diffs will help for this.

Headers!

Install some Evolve Headers and get a nice Ecu evolve map for them. Car will ramp up to 586ps without any worries. Mine had the following

Evolve headers
Supersprint mids
Tubi rumore end mufflers
KN filters on oem airboxes
New spark plugs every 15000km just for the ultimate performance and only 100octane use on it.
Evolve ecu remap

Of course it was completely decat and rev limit was set at 8500rpm. It was pretty quick and very much to my likings.

yeah, i think our M6 is not extremely fast from 0-60 (or even from a 20 to 80 roll) because if you look at the 1/4 mile time the M6 is not that much faster than even a stock STI....but the trap speed at 1/4 mile tells a diff story :-D

Have you look into getting the RPI air scoop? i had one on my 06 Z4M and it was great (with the BMC filter) How's the pulley kit? is the Evo sport a underdrive or just a light weight?

If u have money, get the Dinan modified engine. 612hp output. Sell your old engine back to them to get some cash back.