This seems to be a common question lately. This simple answer is not many. For most cars you will need to keep a log book to ascertain business percentage.
However, utes and vans that are made and registered to carry a tonne or more are  100% tax deductible, no log book required. Dual cabs will generally be 100% tax deductible too, with the requirement being the carrying capacity in the tray must be greater than the passenger carrying capacity i.e. it is more commercial use than passenger use. Any other specific car questions feel free to contact me.
