Get a K&N drop in air filter (est. RM255), better set of suspension (Current ones too SOFT (if you are talking about NON Type-R FD2) - Eg. Hotbits adjustable... Bodykit (MODULO side + front + rear skirting combined with MUGEN Spoiler). Ultra racing (or Eibach anti-roll kit) bar/s.
That's about it if your car's under warranty... If warranty expired... then:
1) Change FULL Set exhaust system...
2) Change to Open POD air filter
3) Change to lighter rims (same size) or 18".
4) PU Bushings
5) Better Brake pads/Calipers/brake hose...
6) Performance Camshafts
7) Remapped ECU OR Piggyback ECU (eg. Dastek Unichip)
There you have it... A car with GREAT PERFORMANCE, Ride and HANDLING, LOOKS (bodykit), BRAKING...