Being able to modify/customize police cars without losing police statut

When modifying a police car, it would be nice that it keep its police statut, so we're able to chase cars in traffic
Especially considering the new lightbars and liveries that has been added (´∀`)

 

It would really be useful, I wanted to modify a police car one day, but it lost its police status

 

Also, setting a police car as the Default car make it lose its police status too