I have $3,500 to upgrade my '11 Mustang GT. What should I get?

I've got about $3,500 to upgrade my 2013 Mustang GT. I was thinking about getting Brembo brakes and Ford Racing Catback exhaust. Any other suggestions?

Added (1). Title is meant to say '13, not '11. I typed too fast on my phone.

Air filter, and exhaust manifolds

Are you running it on a track and getting brake fade? I doubt it. Get your calipers painted yellow if you want people to admire them. Exhaust- what do you use this car for? Real world road driving? If so be careful you don't gain power at the expense of flexibility. Talk to a tuner about an ECU remap and take advice on hardware mods that would compliment that. Don't waste your money on brake calipers.