fleet_car_workshop/views/vehicle.xml

<?xml version="1.0" encoding="utf-8"?>
<openerp>
    <data>
        <template id="assets_backend" name="vehicle assets" inherit_id="web.assets_backend">
            <xpath expr="." position="inside">
                <link rel="stylesheet" href="/fleet_car_workshop/static/src/css/vehicles.css"/>
                <link rel="stylesheet" href="/fleet_car_workshop/static/src/less/car_dashboard.less"/>
            </xpath>
        </template>
    </data>
</openerp>