To make micro-dotting effective, however, requires critical mass. "We can't have border control posts or policing personnel looking for stolen micro-dotted vehicle and parts, when only a fraction of cars on the road are fitted. Micro-dotting must be introduced to as many vehicles as possible - and fast, There is no better way than on vehicle production lines, a practice which will also give uniformity to the unique vehicle VIN number usage, as opposed to mixing of VIN and PIN numbers which can become confusing to law enforcement personnel.