Income tax: motor vehicle substantiation: does the 5000 kilometre limit in section 82KX of the Income Tax Assessment Act 1936 relate to the distance travelled by the car or by the taxpayer?

It is the distance travelled by the owner (taxpayer) in the car that is relevant to the deduction being claimed. Where two or more taxpayers own a car and each uses that car separately for income procucing purposes, each is entitled to claim a deduction using the set rate per kilometre method up to 5000 kilometres because ownership is considered to include both joint and co-ownership within its ordinary non-technical meaning.