Vuex computed property not updating - vuejs2

Question

I am having a hard time trying to update my component state based off a reference Id that I am using to display a result that lives in my store/vuex. Basically, what I want to happen is for when I update a reference ID, my getters/computed passes down the updates value. I have provided a simple version of what I am trying to do with no luck. Any ideas?
What am I doing wrong?
Parent Component file
<template>
<div class="parent"
<Car :car="car" />
<div class="car-btn" #click="switchCarId('11')" >Change Car</div>
</div>
</template>
<script>
import { mapGetters } from 'vuex';
import Car from './Car.vue';
export default {
name: 'Car',
components: { Car },
computed: {
...mapGetters(['car'])
},
methods: {
switchCarId(val) {
this.$store.commit('updateCarReferenceId', val);
}
}
};
</script>
Child Component file
<template>
<div class="car">{{ car.name }} </div>
</template>
<script>
export default {
name: 'Car',
props: { 'car': Object }
};
</script>
Store file
import Vuex from 'vuex';
Vue.use(Vuex);
export default new Vuex.Store({
state: {
selectedCarId: '10',
cars: {
'10': {
name: 'Red Car'
},
'11': {
name: 'Blue Car'
}
}
},
mutations: {
updateCarReferenceId(state, val) {
state.selectedCarId = val;
}
},
getters: {
car: (state, getters) => {
return getters.cars[getters.getSelectedCarId];
},
cars: (state) => {
return state.cars;
},
getSelectedCarId: (state) => {
return state.selectedCarId;
}
}
});

Answer 1

I solved this issue. Turns out deep down in a component I was change changing the value based on a input. So no matter what the state read, it only read it initially. Thanks to Anoatoly for helping me run through it and making sure I dotted my t's and crossing my i's.