Ever buy one new? I'd beg to differ. The quality was sorely lacking, so cheapo in quality, I will grant you that, but when you had interest rates in the double digits (until late 1986 or so) it wasn't cheapo on the wallet. Back then it was mainly 36-48 month loans max. You felt lucky to get away with paying less than $3,000 on interest alone. Back then, I wasn't as liquid as I am now. So a 12K loan wasn't a cheap endeavor.
When I bought my 85 442 new, it was delivered with the front hood corner bumpers in the unlocked position. Found that out later as the hood started to flap more and more as I drove it. I think they forgot to put the limited slip additive in at the factory fill, or not enough as it chirped going around corners. It didn't have the retainer/bolt for the speedometer bullet installed on the side of the transmission, and they forgot to put on the throttle return spring. It just wasn't there. So the quality being cheapo, yeah. It sure was. Luckily all this crap got fixed by the dealer, but it's stuff that shouldn't have had to be fixed. Plus, you only had 12K miles and 12 months to find it, or it was your problem.
The 86 Monte SS had a carburetor issue that made it idle at 2800 rpm or so. They claimed it was primary rod burrs hanging up, but I'm not so sure. They put on a new carb. Then there was the springs in the trunk lock that sprung out (no power trunk lock option) and there were groceries stuck in the back.
As for the license plate deal, those springs are strong and will try and crush the cap. So if it's an old plastic one, be wary. I think the 22525300 (GT172) cap for most G-body gasoline applications 84-up were plastic. Of course, if you have a metal cap, you're golden.
I think they have a kit for the plates that take the normal spring out that you can convert over to a flip down/stay down version. Fairly cheap.