Yes and no. There's a very significant shift underway to move a lot of functionality to Linux. It's very likely that you have at least one kernel somewhere in your car if it was made in the last 5 years. It's essentially guaranteed if your car has ADAS functionality.

Traditional RTOS' are for the most basic, safety critical functionality because the cost of certified (and even QM) code is so high and the tools available are so primitive.