A good portion of the vehicles I owned were GM,s. Only two stand out as being crap. One was a 70 something Custom Deluxe ,I think it had the 305,with the infamous soft cam. Wore out at about 30k. I rebuilt the top end and sold it. The other was an buick skylark that developed a sloppy timing chain that wore a hole through the cover and threw out all the oil.
Had a '76 AMC Pacer that would just quit for no apparent reason. It would start up again sometimes immediately sometimes not for 24 hours.
Had a Ford Maverick that lost the transmission.
Overall most of the vehicles we have owned have been pretty good.
One stand out was a Chevy Lumina sedan,286000 mile, never cost a penny outside of wear and maintenance items.
Another stand out was a 69 Plymouth Fury 1. I got it from my father. Most stripped car I ever saw, 225 slant six, 3 on the tree, no trim no carpet no radio. My father put over 100k on it and I drove it for 4 years while stationed at Camp Lejeune.