From what I have found
Suspension:
Upgrading sway bars make a lot of difference and it is an easy upgrade.
You can update springs, makes a huge difference too but complicated.
Maintenance:
'Oil catch can' can be a good upgrade for a better life of an engine.
Engine:
There are tunes, exhaust and intakes (K&N and Stillen). (Did not look much into it).
Do's:
Love your car, it's your baby.