I realize there are far more ways than one to lose a wheel; it's happened to me once on a factory steel wheel. It's disappointing to find your recently-purchased '74 Charger was apparently used as a lug-nut donor vehicle, and the previous owner put the hubcap back on it with only 3 nuts securing the wheel. That one came off on a 4-lane highway. The unilug incident happened when I was 15, riding with a friend. Not surprisingly, it was a Keystone Klassic that broke (those things were like flies in the '70s and lots were still around years later). The center of the wheel broke out between the lugs. It took out the quarter panel, wheelhouse, and trunk extension on my friend's 'Cuda. I'm sure the wheel had been overtightened or run loose to cause the damage because I whacked a curb with a Keystone at a bad angle while sliding on black ice. It mangled the rim so badly I couldn't believe it held air. Regardless, when the wheel came off my friend's car, neither one of us was even old enough to drive. You want to talk about pit-crew speed getting the spare on?

We were only a few feet from his driveway, but we still freaked. There was no plate, no insurance, and two underage kids. His Dad was not impressed, nor was mine when the call came.
The other reason I don't like unilug wheels is that they don't properly center the wheel on the register. They use the lug nuts and washers instead. That raised area in the center of the axle flange isn't there for good looks.
Interestingly enough, Dave got his car when the previous owner acquired a '78 Trans Am and lost interest in the Fish. The Keystones came on the 'Cuda, which had brand-new cheapo rear shocks. Six years later, I bought a '78 Trans Am from a guy that had knew who'd owned it previously. It had unilug Keystones on it as well. Sure enough, one of the previous owners was the guy that sold Dave the 'Cuda.