Dimples work on golf balls because they influence the way the air adheres to the ball at the back.
The ball needs to be round, so there is nothing that can be done shape wise to reduce the drag; also the ball can rotate in any way, so any measures need to reduce drag need to be omnidirectional.
Dimples do that.
Cars do not need to be perfectly spherical and they move primarily in one direction.
That is why cars do not have the same problem as golf balls; the necessity to use dimples has been designed out, and indeed cars have a way lower Cd than golf balls, even though the latter have dimples.
There is no need for dimples on a car, just as there is no need to hit it with a club
Looking for more videos on golf ball dimples, I was impressed by this one:
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2011 Honda Insight + HID, LEDs, tiny PV panel, extra brake pad return springs, neutral wheel alignment, 44/42 PSI (air), PHEV light (inop), tightened wheel nut.
lifetime FE over 0.2 Gigameter or 0.13 Megamile.
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