My eldest son never had this but I decided to get for my middle son as when he passed his test he went straight into a new car he hadn't driven before and I wanted to give him time to get used to driving it, whilst warning others he may stall or be a tiny bit slower whilst getting used to clutch and gears on a different vehicle. They do exactly what they say, magnetic to car, easy to slap on and pull off. Though I do take them off when not in car as easy for other people to steal! Not the products fault.