I am sure your car has at least exhaust and intake mods. However I am not too sure I would consider those "performance" mods... Since I don't imagine they yield very many ponies per dollar spent (if any).
If you ask me, you have a nice car (slow true, however e90's look quite good) with that said, IF I were in your shoes I would spend the cash on visual mods... maybe a nice drop (to get rid of the 4x4 look), window tint, angel eyes, shawline trim, etc... I wouldn't spend it on miniscule HP gains... but to each their own, it is your money after all.