^^ +1 on Jeff's comments. Heaving done shots like this a bazillion times myself, the more people and equipment you get together, it is (obviously) more difficult, exponentially.
Trying to position the cars and people, and telling them all what to do and not do takes a long time. But, once you start clicking the shutter, and bracketing shots, and changing lights, the people get antsy and start moving...even if just little bit. All of a sudden you have blurred people, and/or a covering (or exposing) of something important, and so on.
Imagine how hard it would be to yell to the guys at the far end of the shop, have them hear you, and do the thing you want. You first have to walk all around and stage everything, talk to everyone. Place the people and their appendages and tools just right. It's not easy.
All of those people have shop jobs that they're now behind on because of this stupid photog (you) who is screwing up their day. So, expect some of them to be at least mildly cranky. And a few of them to be VERY cranky.
Notice that CS and Miles aren't in many of these type of shots. Is Remmy? I'd kinda doubt it. He had real work to do.
Then you get the shots back, and Murphy's Law often has the one best shot messed up by some movement, or something moved out of place.
In the days before computers, about all you could do was to cut and mask the print. Few photogs had real airbrushes to touch up with. Those were mostly with the magazines and ad agencies.
Then, everyone in the photos, once it's all over, wants copies of the prints for themselves. And who pays for that? You, the friendly photog who hopes to get to shoot more pix for the company.