You can complain at any time, but there are different remedies available to you depending on when you complain about the faults.

If you are exercising your 30-day short-term right to reject, you must prove the fault was present at date of delivery.

If you are complaining more than 6 months after receiving the vehicle, you must be able to prove that the faults were present at the point the vehicle was supplied. The law assumes that any faults, if found to exist, would have been present at the point the vehicle was supplied for the first six months of the agreement.