wheel openings

Yes, there's nothing wrong with being stuck in that era but most people don't care for that look anymore. To jack up the rear of the car and hang the meats out 2 inches just looks like it wasn't done properly these days, unless it's an old school build or gasser build where someone was looking for that effect.
Never said anything about jacking up the rear. If you look at Gassers of the late 60s early 70s they were actually slammed at rear with the wheel wells radiused almost all the way to the top of the quarters.
There's also a matter of practicality. On my current Grudge build, I have the wheel openings radiused so that I can pop the wheels off quickly, with nothing in the way.
Its form following function, the way it's supposed to be.