Car radios are generally designed so they can be used without having to look at them. Sure they have displays, but they almost always have a tactile design that allows them to be operated by touch and sound without having to take your eyes off the road.

Smartphones however cannot generally be operated with much precision without having to occasionally look at them, which is why they are becoming increasingly illegal to use while driving. But to your question, I would say no: the same does not apply to most car radios.