The aluminum wheels are coated with a clear protective finish.
Kia Cee'd JD Service Manual: Components and components location
Components
1. Carrier assembly
2. Rear brake assembly
3. Hub & bearing assembly
4. Rear brake disc
...
Kia Cee'd JD Service Manual: Knock Sensor (KS) Specifications
Specification
Item
Specification
Capacitance (pF)
950 ~ 1,350
Resistance (MΩ)
4.87
...