Originally Posted by RonRizz

They still sell them. However, although the arguments will wage on forever, they have been proven time and time again to be pure snake oil. Between the cost of the caps, and the sheer amount of farads you need to actually make any difference whatsoever, you would be better off to add a battery.
Anyone who says a cap helped with headlights dimming (which seemed to be the main marketing strategy) is disillusioned. Its just snake oil, pure and simple.