If I put it into the 12V socket of my car, it pops back out, because the spring from the positive pole is simply too strong. If you hold it with your hand in the socket and a Navi eg inserting it works. You close but still a second consumer to no longer come to enough electricity and the LED glows if at all only. But since there is not even kept within the socket, this is rather beside the point, because when driving normally I use both hands and have no desire to have, for example, constantly hold while traveling the scrap.
Conclusion: Buy yourself something else, the thing here is just garbage !!!!!
PS: If it were possible I would give no stars, because even one is too much already. Take the coal dear and goes tipping a few beers. There you have a lot more of!