The car headlights only look dim in comparison to the HID (though Car A needs re-aiming); I've done this a bunch of times out on desert roads, using an HID to light up a half mile of road and the entire roadway hillside, then a car comes from behind and I turn off the light - suddenly all that's left is the car's headlights lighting up only the paltry few hundred square feet directly in front of the car, it's a difference of many orders of magnitude. Sometimes after I turned off the light, the car would then turn on their high beams trying to get the initial amount of light back, but to no avail..