In the course of a discussion of the deductibility of home office and automobile expense of an independent contractor where the property is held in co-ownership, CRA stated:
[S]ection 67.4 provides an additional rule in respect of a motor vehicle owned by more than one person. Under that section, where a person owns a motor vehicle jointly with one or more other persons, the reference in paragraph 13(7)(g) to the amount of $30,000 is replaced by the product of the multiplication of that amount, by the ratio between the FMV of the person's interest in the vehicle and the FMV of the interests in the vehicle of all those persons.
For example, if a taxpayer has a $60,000 interest in a passenger vehicle worth $80,000, under section 67.4, the amount of $30,000 in paragraph 13(7)(g) which would be applicable to that taxpayer is $22,500 ($60,000 divided by $80,000, and multiplied by $30,000.)