LEDs use extremely little power, not even close to the original lightbulbs. them flickering is simply your cars engine starting which requires a lot of juice from the battery in a short period of time. just like how you might notice your dash lights dim a little if you turn on your high beams or turn up your audio. power is a quantity and is used per second, and starting a car takes a LOT of that quantity for a few seconds.

 

i just noticed the same with mine last night!! They are very dim. But its only the front map lights not the back, IDK. Lights still are working fine when i turn them on and when i open the doors.
I just installed mine last week.

 

Its fine ..... mine is still doing it after a month and its normal