No a classic R129 500SL.
Well I bring it to the Audio shop- Its not the wiring accodring to him- But a weak battery or alternator.
What I notice- It happens during night- When light is switch on. Brake need power to light up the rear lights.During day time- It's OK.
I'm guessing the battery. I will have that check soon after raya. Check the voltage on the alternator & battery.
I hope the Audio man is correct.