You need to keep a log book for the first income year for which you use this method for the *car.
Having kept a log book for one income year, you don't need to keep a new one for the next 4 or more income years unless subsection (3) or (4) requires it. If you haven't kept a new log book for 4 income years in a row, you must keep one for the next income year.
If you keep a log book in 1997-98, you would need to keep the next one in 2002-2003, unless subsection (3) or (4) requires one sooner.
You must keep a log book for an income year if the Commissioner sends you a notice before the year directing you to keep a log book for the *car for that year.
You must keep a log book for an income year if, during that year, you get one or more additional *cars for which you want to use the ``log book'' method for that year.
When you replace one *car with another, you might have a period when you *hold both the new car and the old car, or a period when you no longer *hold the old car but do not yet hold the new car. In both these cases, you are treated for the purposes of subsection (4) as if you held the one car continuously.
You may choose to keep a log book for an income year even if you don't need to; for example, because you want to establish a higher *business use percentage.