select list returns previous value after closing and reopening

Question

I have a list and I choose a value from the list.

For example "Mercedes".

But I close this list with the "Save" or "Close" button and when I open it again, "Mercedes" is selected. How can I prevent this?

    <Modal isOpen={app.showCars} >
        <ModalHeader>
        </ModalHeader>

        <ModalBody>
            <Select
                options={carList}
                onChange={(car) => (app.addcar = car)}
                value={app.addcar }
            />
        </ModalBody>

        <ModalFooter>
            <Button onClick={() => {
                app.addcar()
                app.showCarModal = false;
            }}>Save</Button>

            <Button onClick={() => {
                app.showCarModal = false;
            }}> Close </Button>
        </ModalFooter>
    </Modal>