I've seen a lightning hit a back of a straight truck just in front of me (in the left lane, I was in right), while driving at around 45 mph. But the lightning had hit the ground first, then bounced back, hit the back bumper of the truck. Created a loud bang and sparks like someone was cutting off the bumper with a torch. I saw the driver pull off to the median and the car just behind it too, the driver was visually shaking.
This was in AZ on the way to Tucson during monsoon season, the year of our lord 2005.
AZ is one of the top states with the most lightnings.