It was unbelievably reckless for the Cleveland cop to drive the car right up to what has been reported as an armed man, and skid to a stop with the cop on the passenger side fully exposed in the potential line of fire. This could well have been fatal for the second officer if Tamir had been an actual bad guy rather than a child.
The more normal procedure would be to stop the car as soon as you recognize the subject, and as close to some kind of additional cover as possible. The car should be pointed straight at the subject so the officers can use the doors for cover while they get out. Once behind cover, the officers can challenge the subject from there.