The Vega design had numerous issues. The block fabrication error was one. The heads also tended to warp, the cooling system capacity was inadequate (a recall was issued but I’d already modified mine by the time it came out), the idle stop solenoid bracket would break and the solenoid fall into the accelerator linkage (again, the recall came out after I modded mine), the plastic valance panels were so cheap that hook & strap-type tow trucks (common back then) required a release to be signed 'cause the straps would crush the panels to bits, and…the biggie…the retainer in the rear alxe assembly (the one inside the carrier case that holds the axle in) would fall off and the axle with wheel would slide right out of the axle housing. Yeah, they had a recall. Yup, I had mine checked…at two different places. Yup, it came out anyway. You haven’t lived until you’ve had your axle slide right out of the assembly while you’re rolling.
Also, on mine, after only four years and 74,000 miles the trany had self destructed…the tranny was never properly bolted to the bell housing, sitting at a slight angle with loose bolts, the seat back was falling off the seat (and I only weighed 135 lbs back then!), and I had to lift the door to close it…the hinges were shot.
I dumped mine the day after I put the axle back together. Traded it for a Corolla. The Corolla ran flawlessly for years until I finally had to trade it for a 4-door when my second was born.
And we wonder why GM is in trouble!