from my personal experince with GM.... and why i'll never own another.
I come from a chevy family. my parents pretty much will only buy a chevy mainly because they are cheap and have a GM discount from my grandfather.
the motors- are fine, and are perfectly reliable. then run good, smooth, and make good power for the most part *cough 2.8 v6 cough*
however, its the rest of the car that just falls apart.
my moms 94 lumina euro has 130k on it. you could eat off the interior. I doubt the car has ever seen 80mph.
and yet, she needs new brakes, (rotors and pads) ohh, about 3 times a year.
my dads old 88 blazer- 2.8 v6 4wd. 110k miles. on its 4th transmision rebuild. never towed anything bigger than a "garbage/dump/brush" trailer.
my dads 00 s10 zr2 without the zr2 (some tahoe package-- bigger wheels, etc). 40k miles steering clicks, 4wd knocks, and the shift smotheness of it blows.
my old 94 cavalier z24 3.1 v6. bought it with 30k. never put a dime into it. at 65k, i was hit- and thank god.
passenger side window wouldn't go down... and if it went down, it wouldn't go back up. track was fucked.
radio area was craking. seats were wearing fast.
everything rattled- especailly the sunroof area.
trunk leaked
but, mecahnically, it was fine. gave me 35k of $10 oil changes and a K&N filter.
the rest of the plastic car, sucked.