Which Box Is The Car In?

The answer is Box two.
The aim is to work out which statement is correct by the process of elimination.

Therefore:
If the car was in Box one, that would mean that the statements on Box one and Box three were both correct.

Similarly, if the car was in Box three, that would mean the statements on Box two and Box three were both correct.

However, if the car is in Box two, then the only statement which is true is the one written on Box three, The car is not in Box one.