For drivability, for me it has to be having an UpRev tune, benefits are that it lifts the factory throttle restriction on the first three gears and the hidden bonus here is that the 155mph limit goes on extended vacation never to be seen again.
Visually....I love my Volks, like really love them, because they are one of the biggest visual impact you make to a car.
Most recently my newest addition of the Invidia Exhaust has given me renewed joy in the higher revs after having had two JapSpeed systems before (which really are regretful choices in hindsight)
All the other bits just work together to show my individual expression of what I find makes a good looking Zed.