The part is something of useless, unless you're driving in bright daylight. Especially in winter you drive morning and evening at dusk or in the dark of / home. And if there is no device to the USB cable depends, the blue ring flashes in Sekundentakt.Bei darkness disturbs this extreme - one thinks that somewhere driving a police car, so it is bright and reflects on dieversen parts throughout the interior. Why not to use, because you switched on permanently and unplug should.
