Extra step when departing via Shenzhen Bay checkpoint via private car
Experienced this for the first time back in October 2018 going to HKG. When exiting China at Shenzhen Bay checkpoint, all cars are funneled into a single line after the first set of booths, which are now vacant. Passengers are brought to a small building setup in the second line of booths and have to exit the vehicle. Inside the building are a few agents who will process your exit. The car comes around the other side to pick up the passengers. Personal baggage can be left inside the car.
It's a scaled down version of the changes instituted in 2017 where all vehicle passengers must now exit the vehicle and using the immigration counters inside the main hall. I have no idea if the same procedure is being used at Huanggang checkpoint, as I haven't exited from there in a private car since earlier last year. They did not take fingerprints during exit but I assume the change in procedure has something to do with facial recognition.
Overall the procedure is quick and not as much of a hassle as the change in entry procedure with having to use the main hall. If it is slower, it seems not by much. I'll be transiting on Friday before Lunar New Year, so I expect the crowd level to be higher than normal. I've used Shenzhen Bay a few days before Lunar New Year before, so I''ll have some frame of reference.