嵌入表单是实体类型字段

I have a Car entity embedded in Person entity.

 // PersonType.php
public function buildForm(FormBuilderInterface $builder, array $options)
{
    $builder->add('name')
            ->add('age')       
            ->add('car',CarType::class)
            ;
}

// CarType.php

public function buildForm(FormBuilderInterface $builder, array $options)
{
    $builder
        ->add('marka',EntityType::class, array(
            'class' => 'FormularzeBundle:User2','choice_label' => 'age'
        ))
        ->add('model',EntityType::class, array(
            'class' => 'FormularzeBundle:Car',
            'choice_value' => 'model'
        ))
        ->add('rok')
    ;
}

///Car entity


class Car {

/**
 * @var int
 *
 * @ORM\Column(name="id", type="integer")
 * @ORM\Id
 * @ORM\GeneratedValue(strategy="AUTO")
 */
private $id;

/**
 * @var string
 *
 * @ORM\Column(name="marka", type="string", length=255)
 */
private $marka;

/**
 * @var string
 *
 * @ORM\Column(name="model", type="string", length=255)
 */
private $model;

/**
 * @var int
 *
 * @ORM\Column(name="rok", type="integer")
 */
private $rok;

/**
 * @ORM\OneToMany(targetEntity="Person", mappedBy="car")
 */

private $persons;

public function __construct()
{
    $this->products = new ArrayCollection();
}


/**
 * Get id
 *
 * @return integer 
 */
public function getId() {
    return $this->id;
}

/**
 * Set marka
 *
 * @param string $marka
 * @return Car
 */
public function setMarka($marka) {
    $this->marka = $marka;

    return $this;
}

/**
 * Get marka
 *
 * @return string 
 */
public function getMarka() {
    return $this->marka;
}

/**
 * Set model
 *
 * @param string $model
 * @return Car
 */
public function setModel($model) {
    $this->model = $model;

    return $this;
}

/**
 * Get model
 *
 * @return string 
 */
public function getModel() {
    return $this->model;
}

/**
 * Set rok
 *
 * @param integer $rok
 * @return Car
 */
public function setRok($rok) {
    $this->rok = $rok;

    return $this;
}

/**
 * Get rok
 *
 * @return integer 
 */
public function getRok() {
    return $this->rok;
}

/**
 * Set person
 *
 * @param \FormularzeBundle\Entity\Person $person
 * @return Car
 */
public function setPerson(\FormularzeBundle\Entity\Person $person = null) {
    $this->person = $person;

    return $this;
}

/**
 * Get person
 *
 * @return \FormularzeBundle\Entity\Person 
 */
public function getPerson() {
    return $this->person;
}


/**
 * Add persons
 *
 * @param \FormularzeBundle\Entity\Person $persons
 * @return Car
 */
public function addPerson(\FormularzeBundle\Entity\Person $persons)
{
    $this->persons[] = $persons;

    return $this;
}

/**
 * Remove persons
 *
 * @param \FormularzeBundle\Entity\Person $persons
 */
public function removePerson(\FormularzeBundle\Entity\Person $persons)
{
    $this->persons->removeElement($persons);
}

/**
 * Get persons
 *
 * @return \Doctrine\Common\Collections\Collection 
 */
public function getPersons()
{
    return $this->persons;
}

public function __toString() {
return $this->marka;
 }
}

Via CarType 'model' property I would like to insert to database a value from 'model' property of FormularzeBundle:Car but I always insert different one (value from 'producer' property). I'm setting choice_value' => 'model' but it is not working.

Thank you in advance for help.