It could also be reflection from something, soffit, that plate on the car, something else close to the camera like a brightly reflective wall? Try adjusting the focal point up or down and see if it improves
I'm not a dome expert so hopefully someone with more experience with them will drop by..
I had the same issue, was definitely due to a reflection from a barn style door that when closed will cause a reflection. ( notice left side) Initially it was much closer than the picture shows it I have sinced moved it further out and the night picture is much better I will upload an image tonight. I resolved issue by moving camera further out
Dahua's method of sealing off the lens from dome is much more fool proof.
They use a rubber ring mounted to the lens, that presses firmly against the dome.
No foam to mess with.