Xemplifi

Hello, I need help understanding the difference between

1. Rear bumper
2. Rear bar
3. Rear valences

I'm talking about the S14 zenki to be more direct, but from my understanding rear aero is not particular to either the Koukis and Zenkis.

If I wanted to buy new rear aero, should I be looking for all 3 or specifically a rear bar and valences???

Thanks