Hate to say it but GM has piss poor body engineering. I've owned quite a few GM vehicles including vans and trucks for a business. What I've learned about GM over the years: drivetrain is pretty stout mechanically. Rarely had big problems with engines or transmissions and they will last 10+ years and 100k+ hard city miles. Everything else is crap. You spend a lot of time fixing little things. Broken plastic bits in the cabin are the first items (dash and door pieces) followed by silly things like door handles, hoses, small plastic bits on/around the engine, and other minor yet highly aggravating issues.

And don't get me started on their sad excuse for door handles. They've been producing cheap trash designs since the 90's. Even my old 95 Tahoe suffered a few broken door handles. They can't help but make a flimsy plastic carrier and a thin flimsy cast zinc handle that fails after a few years. The usual culprit is a small thin bit of plastic which holds the whole thing together breaks or the handle snaps from mechanical fatigue. It's laughably pathetic and partly why I won't ever touch another GM ever again.

GM in a nutshell: A decent drivetrain surrounded by plastic trash.