This examples shows how to implement a basic search screen in Android Auto

import android.util.Log
import androidx.car.app.CarContext
import androidx.car.app.Screen
import androidx.car.app.model.SearchTemplate
import androidx.car.app.model.Template
import com.your_package.automotive.AndroidAutoSession

class SearchDestinationScreen(
    carContext: CarContext,
    private val session: AndroidAutoSession,
    private val screenId: String
) : Screen(carContext), SearchTemplate.SearchCallback {
    override fun onSearchSubmitted(searchText: String) {
        Log.d(TAG, "onSearchSubmitted triggered: $searchText")
    }

    override fun onSearchTextChanged(searchText: String) {
        Log.d(TAG, "onSearchTextChanged triggered: $searchText")
    }

    override fun onGetTemplate(): Template {
        val searchTemplate = SearchTemplate.Builder(this)
        return searchTemplate.build()
    }

    companion object {
        const val TAG = "SearchDestinationScreen"
    }

}

Source : https://github.com/android/car-samples/blob/main/car_app_library/navigation/common/src/main/java/androidx/car/app/sample/navigation/common/car/SearchScreen.java