Sort of.  Most cars since about 1975 don't have frames.
The thick neg. wire attaches to the engine because of the starter amp draw.
The thin neg. wire attaches to a fender or brace.
For a general schematic, I've always found libraries to be very helpful.
They have books on cars.  Motors, Chiltons, Haynes, etc.
And what they don't have, they can get.
Except for Canada.