Mine was noisy when I switched on the radio and it clack-clack clack on the way up. Does this on the way down too with a few more closing clacks at the end. One day I took my car to a Benz dealer and they were supposed to fix this and other things. When I drove off and approached a traffic light, I duly switched on my radio and to my embarassment, the aerial shot out like a speargun and hung by the side of the car! The dealer offered to put it back in without any replacement due to their bad workmanship and said I had to pay for a new one if thats what I wished. I went to an independent tech and he put in a new Benz aerial piece cheaper than the dealer, but the noise is still there, but far quieter. Has to be the gear inside and the motor which may have to be replaced at a high cost. Leave it! Only listen to the radio for traffic reports thats all. Just wonder how the Japanese cars can have such quiet and smoothly operating radio antennaes?