The panels are primarily used to show where a car is in the pecking order. However, they have extra capabilities.
The panels will change colour accordingly in practice, qualifying, and races.
In practice and qualifying, the panel will change to purple when the car sets the fastest lap, as pictured below.
For the Sandown 500 and Bathurst 1000 they have extra importance with different colours denoting whether the primary driver or co-driver is in the car.
The panel will stay yellow when the primary driver is in their car and will change to greenish blue when the co-driver is onboard.
Before Gen3, Supercars used a single green light at the bottom of the windscreen to signal the co-driver was onboard.
Manufactured by Australian company MoTeC, the panels debuted in 2023 at Wanneroo Raceway after lengthy delays induced by COVID-19.
The system was first trialled in 2022 on the Gen3 prototypes.
LED panel colours explained:
YELLOW: Primary driver in-car
CYAN: Co-driver in-car
PURPLE: Fastest overall