VIN:

Identifier	Code	Details
World Manufacturer Identifier (1-3)	1FA	Ford, USA, passenger car
Restraint System Type (4)	F	Active safety belts ? all positions, second generation air bags.
Vehicle Type (5)	P	Passenger Car ? Ford North American Vehicles
Line, series, body type (6-7)	40	Mustang (2-door coupe, Base)
Engine type (8)	4	3.8L, EFI, six cylinder
Check digit (9)	2	is valid (see below)
Vehicle Model Year (10)	X	1999
Assembly Plant (11)	F	Dearborn, Michigan (USA)
Production Sequence Number (12-17)	141536	Note: consecutive unit numbering began at 100001

VIN Check Digit is calculated by applying a formula to the other 16 digits of the VIN. If the calculated value and the value you have entered do not match then there is a mistake in the VIN (or the calculation). However, a match does not prove the VIN is correct, because there is still a 1 in 11 chance of any two distinct VINs having a matching check digit. See here for more information on VINs and their check digits.