The 1970 dash is held together with just short of one million sheet metal screws.
The grille looks like it was made in a college class.
The doors rattled even when brand new. One of the Chrysler bosses slammed a Challenger door and when he heard the sound it made (more like a clatter than a clunk) he realised straight away that the quality was rubbish and that people would see that.
Hell yeah sales dropped. They were supposed to sell 200,000 a year.
Figures were (very aprox) 77,000 in 1970 and then only 27,000 in 1971.
But you are right. Things only got slightly better quality wise. That was because the decision to stop production sometime after 1972 had already been taken before the 1970 model was even released.