Note that
<input type="text" id="car" required="true" />
is wrong, it should be one of
<input type="text" id="car" required />
<input type="text" id="car" required="" />
<input type="text" id="car" required='' />
<input type="text" id="car" required=required />
<input type="text" id="car" required="required" />
<input type="text" id="car" required='required' />
This is because the true value suggests that the false value will make the form control optional, which is not the case.