This USB Adapter from Belkin has always works properly - if it fit because in the cigarette lighter. After we have often used the part in an old Audi A4, I wanted to use it in my Opel Corsa B. Sorry, there was not. The contacts are not touched. My cigarette lighter has been tested time and it worked as it should. It was disappointing as I had counted on the small Belkin on the trip - not nice. I do not know if it was because of my car (though I've never had problems with the lighter, also with other devices) or at Belkin.
Anyway, the Audi he works so well and also on the boat in a separate cigarette lighter adapter, hanging from a battery, everything went great.