Starting in the 2006 model year, the dark car option is enabled/disabled using the ford ids laptop and vcm to connect to your vehicle and electronically alter the module preferences inside the lcm. Unfortunetly, for most crown vic owners this will mean a trip to your local ford dealer's service department. However, if you are a large volume shop, regularly want to be able to toggle the dark car feature, and can justify spending a few thousand dollars, you can purchase a vcm and the ids software subscription from
www.motorcraftservice.com. For some screenshots of a 2008 ford crown victoria police interceptor having the domelights enabled with the ford ids scantool, click here.