Electrical across all generations
Mk1
Simple relay-based electrical system, highly reliable when maintained.
Mk2
More complex than Mk1 with Motronic fuel injection.
Mk3
OBDI standard, more electronic integration.
Mk4
OBDII standard, CAN bus beginning.
Mk5
Full CAN bus, more integration.
Mk6
MIB infotainment, more electronics.
Mk7
Full digital integration, virtual cockpit.
Mk8
Fully digital, minimal physical buttons.
Type 1 / Beetle
6V system originally, positive ground.
Type 2 / Bus
Evolution from 6V to 12V.