I did, it doesnt work.
<Vehicle>
<!-- The name of the vehicle. This should match the vehicle's model name in the game. -->
<Name>SLR19TAH</Name>
<!--
List of extras available for the vehicle.
Each extra is defined by an ID and an enabled status.
-->
<Extras>
<Extra id="1" enabled="true" />
<Extra id="2" enabled="true" />
<Extra id="3" enabled="true" />
<Extra id="4" enabled="true" />
</Extras>
</Vehicle>
</Vehicles>