There is actually a big security push in automotive that's sort of been slowly coming to the fore over the last few years. It's not the OEMs that are driving it

There is actually a big security push in automotive that's sort of been slowly coming to the fore over the last few years. It's not the OEMs that are driving it really either, they are to some degree, but it's the suppliers starting to make security hardware and system protection available, as it really hasn't been for very long. It's still not really entirely there. Basic things like the microcontrollers and CAN hardware / protocol never had security designed in. No one was willing to invest significant engineering time or do expensive security in software when hardware cost is king, or even invest in the engineering cost of bringing in security from suppliers (seriously, there's like 20+ independent computers in your car and it's going to be 50+ on average soon if it isn't already and out of those you'd probably have to harden 10 or so, or introduce entire new ECUs) There's a number of solutions but none of them are cheap. As hardware support becomes widely available, development time for higher tier suppliers drops and they can economically offer secure solutions, and with scares like the Jeep remote control hack in 2015 and with cars getting more connected, OEMs are starting to see the business case for security.