It's probably difficult to retrofit. CCS provides different wire harnesses in the vehicle for AC and DC power. NACS requires shared conductors for AC and DC pow

It's probably difficult to retrofit. CCS provides different wire harnesses in the vehicle for AC and DC power. NACS requires shared conductors for AC and DC power from the charge port to some point that can handle switching between them. External adapters are simple and will be available, since you can have different adapters for AC and DC charging to avoid needing active switching.