I've noticed this with the LED strip on the lower front bumper of newer Mercedes cars. I'm pretty sure the DOT requires that your headlights don't blink, so I

I've noticed this with the LED strip on the lower front bumper of newer Mercedes cars. I'm pretty sure the DOT requires that your headlights don't blink, so I wonder how low the PWM frequency can be until they consider it blinking? I also wonder whether they do it on purpose. How hard would it be to run the PWM at a few kHz instead of the < 100 Hz frequency it seems like they're using?