In the big picture, yes, there are certainly things that the car manufacturers can do. Some are taking this more seriously than others.
Since 2016 and before, some of the car companies and OEMs actually started looking into the issues of cybersecurity. However, the technology is advancing much faster than we can find the loopholes in the security and fix it. A lot of times when the car is on the market, the security loopholes are just identified. We are playing a game of cat and mouse a bit with this feature, and that could be one of the reasons why the carmakers are falling behind. The process of adjusting their technology might take them some time to get into the market. That could be one of the reasons.