There's no bonuses at all on series 2's. Series 1's are getting some bonuses, plus most of them are cheaper at RRP, plus the reluctance of dealers to seriously discounted results in higher transaction prices.
On an Sv6 the difference is around $3,000. On other models it's more. Plus you don't get the free servicing offer.
If you really want one, unfortunately you'll have to pay. I can't see them discounting until January, and if it's anything like last year it will be $500 on 2015 plated cars.
We drove them around the race track today as part of our product training. The V8 sounds great, but the real world drive doesn't seem that much different to me. You don't get much noise in the cabin still, but they're bloody noisy outside of the car. The $1500 difference in RRP easily makes up for the cost of an exhaust, plus most of them have picked up extra features.