I, too, have a VW with such visor lights, and I, too, have probably used them less than once per year in the last 7 years.

So if a friend borrowed my car and (somehow, improbably) 'broke' them somehow... I might not notice for months.

Are you sure they were working when you dropped the car at FlightCar? (Was one of the 3 times in 10 years that you used the visor-lights that same day, or was checking both part of the explicit check-in inspection?)