For my birthday, september 11

, my awesome, not to mention HOT girlfriend wants to buy me something for my car...It's a 2002 Mustang GT 5 speed with 3,000 miles on it. Now I don't know what I should ask her for...I have the K & N air filter with the air silencer removed, and flowmaster 40 series 2 chamber mufflers, which sound great. I was either thinking of a 3.73 rear, pullies, MAF, or whatever else is under $200'ish. Another buddy of mine ordered me the Bullitt shiftknob, the Bullitt shift bezel, and the Bullitt door locks.
I REALLY need your input on my next mod...Obviously I want the most power out of my next mod, somethign that I will actually feel. Thanks.