The Cadillac system from 50 years ago (yes, 1967- 50 years) was far more effective. It used fiber optics to monitor actual lamp output instead of electrical load, and reported that to the driver. In another 20-30 years, perhaps the vaunted German engineering will catch up to old Detroit, err, Flint.
In the interim, check ALL the rear lamps, including the dual license lamps, side markers, etc.