1978. The beginning of the metal to
plastic transition. All manufacturers
we're scrambling for ways to meet
EPA'S gas mileage requirements
to lighten the load, and were more
or less forced into using lower
quality parts. Plastic replaced almost
every part in the dash, right down to
the ashtray. (remember those?)
Plastic parts composition those days
would see rapid deterioration due to
UV and heat. The worst I've witnessed
was a '81 vette with t-tops. The guage
bezels twisted so bad the needles
wouldn't move, the glovebox door
wouldn't close, the bottoms of the
cup holders were broken out.
Almost all American car
manufacturers sourced their plastic
parts from the same suppliers, the
quality, or lack thereof, affected them
all.