All exterior lights on car need to have an 'e' mark on them, then they are approved for road use.
The lights carrying such a mark (including head- and taillights) were tested by a member state (number behind the e tells you country that gave approval) approved testing station with the manufacturer specified light bulbs, xenons (not HID aftermarket kits from China) or complete LED clusters (not LED 'bulbs').
99% off the stuff on eBay won't be road legal.