I just pulled a 1977 Chevrolet Impala for grins.
So what did you learn about my car? Last time I checked which is about 5 years ago they had nothing for my car. All wiring and installation except for the twin shaft radio/cassette was custom only.
BTW the only two wires I reused was the ground and hot/key. All other wiring is custom from the trunk forward. It had a single speaker am/fm radio. Now has CD/radio and 4 way speaker system.