[0x457]

It's so hard that (almost) every European manufacturer figured it out.

There is also FlexRay. There is nothing interesting you can do with CANbus on new mercs. Even unencrypted CANbus messages go through gateways that (could) prevent headlights from reporting key presence.

There is a reason that some cars don't have reasonable attack vectors (excluding parachuting the driver out of the car) and some can be started with a screwdriver (or slight more involved way with CANbus). It's not complexity, it's cost.

[K0balt]

Absolutely. Margins on cars are surprisingly thin at the manufacturer level.