wrongly positioned carpet padding... sounds like human error to me and not a build quality issue whenit comes to type of material that was used. If anything is installed improperly it can cause issues.
Then it's a worker quality issue, it's not just one or two vehicles it's 8,000+ I own a Ford vehicle (Mercury Mountaineer to be exact) so many original parts made with cheap plastic that broke down. Especially one major problem with the harmonic balancer. The damn thing was half rubber half metal, the metal part separated from the rubber wheel which made the s belt ride the inner rubber part. There's also the mysterious crack on the back plastic panel everyone deals with and the cheap paintjob which after 4 years of use started chipping away from simple car washes. Just no effort in making quality products.