Time to time I experienced dimming of lights and accessories for a few seconds, sometimes with erratic running of the engine at the same time. Seemed especially likely with a warm engine when coming down to idle after a run (like getting off highway and entering stop-and-go city traffic). Maybe worse in wet weather. Definitely worse with lots of accessories on or when stepping on the brake pedal. I don't refer to the LED gauge needles which many have posted on - rather it seems to be the whole system. On the alternator I took off the rear cover, voltage regulator and brush holder - there was a great deal of filth on the slip rings and they were also scored all the way around to the point I could feel the grooves with a finger. I have had a similar issue on a couple of other cars in the past. Anyway, I cleaned everything up. It will take a few weeks to know if this helps. Meanwhile I thought it was worth mentioning in case other owners might have the same issue. Sooner or later a new alternator might be needed.