A case in point. I took this shot yesterday. Equipment used: Sony NEX-6, Metabones NEX-FD Speed booster, Sigma FDn 70-210mm 3.5-4.5 APO. Manual everything (save the white balance). And no cropping.
That is a good example - you clipped the front of the car. If you had shot wider you could have got all of the car and then cropped for better composition in post.
I can understand how you could shoot motorsports with the "no cropping" limitation, I just don't understand why you would. Cropping is one of the major tools of photography. Not using it is like a finish carpenter not using a chisel or planer and justifying it by saying he gets his cuts right the first time (but throws away a lot of good wood).
There's this weird trend in online photography discussion groups where mediocre photographers embrace some sort of artificial limitation regime like "no cropping" or "primes only" because of the belief that it's purer photography or something. Like, I get that sometimes it might be a good idea to set a temporary artificial limit in order to break a bad habit but making those limits SOP is nonsense, imo. Knowing how to appropriately use all of the tools available to you is what makes you a better photographer, not arbitrarily throwing out some of the tools from the bag. See also "I don't use photoshop/shoot RAW, I get it right in camera" or "I don't need a flash, I prefer natural light"
This is a tangled knuckleball of sensibilities and issues you are throwing to us. (But it's a fun pitch to swing at, I admit.
For me, natural light vs. flash is about (a) how much effort and how many variables do I want to control, (b) how much gear I want to carry, and (c) how deliberate vs. spontaneous I want the shot to be. My answers to those three questions are (a) little effort / keep it simple, (b) less gear, and (c) usually spontaneous. So natural light shooting is what I strongly prefer.
For getting it right in-camera vs. cropping, that's a question of whether you enjoy working within the limitations of your gear (the guy who brings one lens and moves his feet) or if you see limitations as unacceptable constraints that will be eliminated with more lenses, more post-processing, etc. Crudely, and likely unfairly, I think the first group wants to puff up their chest and show how competent they are at thinking on their feet and netting difficult shots under tough constraints, and the second group giggles at that and either changes lenses or just crops the shot. One viewpoint is proud and determined and the other is pragmatic and efficient. Neither are right and neither are wrong.
As for post-processing, I think it strongly depends on what you shoot and how much time you want to spend shining up your work rather than collecting more images. With controlled lighting, consistent sort of subjects, etc. getting it right in-camera is a small matter of dialing it in. But I don't go to 'shoots' where my environment is scripted. I happen to shoot my life around me, and my subjects are moving, impatient, and inconsistently lit. So I shoot JPEG + RAW, and I screen with JPEGs and process the 3-5% best RAW shots individually. That lets my photographic reality be tamed to the point where I get the most out of my shots at a fraction of the work needed to process them all.