goddamn the car looks like it just rolled out of the factory.... Love black when its clean!
As a fellow e92 328, i'd suggest starting with cosmetic modifications first because the $ : HP ratio is not so great. If i were you, I'd get some new rims and then dress it up in M-Sport gear.
If you want to do performance you should check what motor your running first. If you don't know how to find out, pop your hood and there will be a sticker under the hood that'll say ULEV or SULEV. ULEV - N52. SULEV - N51.
If you have an N52 then get a 3-stage intake manifold and AA tune first. If you have an N51 then it comes with the 3-stage intake manifold already so you can just tune it off the bat, or go for an exhaust of your choice.
Whatever you do, it should be pretty hard to mess up what your working with, the black looks absolutely pristine