Too long to explain now. In short

1. they want a new car, and they like to change cars every three or four years under novated lease.

2. save tax (not much), even they have to compensate the company for FBT contribution and GST on the FBT contribution.

If you are on $80K, your car base value if $30K, if you drive it for less 15000 kilo, you can save about $900. But if you drive it for 40000 kilo, you can save about $4,800.