As others have said, find out who the company is that's doing the novated lease and speak to them. I was new to Aus when I did mine, so didn't know the tax laws here (But have a good understanding of finance and tax laws in other countries so I could ask lots of questions!) but the advisor explained everything, did the savings calculations (and explained them to me so I could see they were both accurate and how they worked) showing I'd save significantly leasing my just bought D3 back to them!!
Basically, it allows you to pay for lease and operating costs of the vehicle from your gross (pre-tax) salary, and avoid paying GST on them. If you are in a higher tax band, this outweighs the additional cost of the lease over a cash purchase. If you also travel a good distance (Typically reckoned to be over 25k km's a year) you reduce the FBT liability too.
Bear in mind you do get a residual payment at the end of the lease that you owe on the car though, and it's your responsibility to pay this and then own the car, or sell the car to pay this. Not a problem if you're rolling it into a new lease, as they're calculated to be less than the trade-in, but worth thinking about. I just stuck the money that I would have used for a car purchase in an offset account so I'm saving the mortage interest on it too! 
For me, coming from the UK where you get screwed on both company cars and car allowances, Novated leasing is the best thing since sliced bread!
Jeff
1994 300TDi Defender
2010 TDV8 RRS
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