This mysterious number is found on a plate or sticker as well as engraved on the body in letters about 1 cm high. Its digits can be broken down to give details of car make and model type, year and place of manufacture and serial number. 993 Volkswagen Polo Est. This is found on the front panel by the engine cover lock, or on the inner wing. It is a rivetted plate about 8 cm by 4 cm.
Recent models seem to have an adhesive sticker instead.
It also has the production codes on it, as found on the production plate. Newer models have it on a sticker on the suspension turrets, inner wings or other places.