I saw for the first time a green light at the back of the cars in F1. Why is it there and what is its purpose? 12 cylinders or walk
If you're talking at the very back - it's not a light, it's fluorescent green tape at the bottom of the rain light. Not sure why it's there... maybe to differentiate a car (I saw it on the McLaren), or perhaps a non-naturally-occurring color so that it can be easily detected in pictures, or by camera, or by laser or something (like for timing, tracking, etc).
Also, not every car had the green tape. Stange since the FIA has rules about everything. 12 cylinders or walk