To calculate the overall star rating and percentage breakdown by star, we don’t use a simple average. Instead, our system considers things like how recent a review is and if the reviewer bought the item on Amazon. It also analyses reviews to verify trustworthiness.
I installed on in two different cars. One, that is only powered on when the key is engaged and the other that is constantly on. The one powered by the ignition is great but the always on is killing the battery. Have ordered one with a toggle switch and will swap it out.