The top of the page shows a Daimler sales brochure from around 1970 with the caption "The DS420 of the English Royal Court is distinguished by a blue light on the roof (padiglione=~pavillion), and the spotlights in the cockpit (abitacolo)". But the car on that brochure-picture belongs to the Danish Royal Court, it is a left hand drive one, and it has no blue light at all...