The all-new NX has already attracted more pre-release orders than any other Lexus, despite being five months ahead of its Australian launch in late October.

That has led Lexus to state publicly that the new mid-size SUV will be one of its top-three sellers; alongside the IS medium sedan and RX large SUV.

Privately, however, Lexus Australia CEO Sean Hanley believes the NX has what it takes to overtake both the IS and the larger RX as the brand's top-seller in SUV-mad Australia – and to lead the Japanese luxury brand into a new sales era.

"NX has attracted more pre-launch interest than any other Lexus," Hanley told motoring.com.au at this week's Whistler (Canada) launch of the new compact luxury SUV.

"It will be the first step in Lexus going to the next level and I personally don't see why it won't become our biggest [selling] model."

The NX goes on sale here around the same time Lexus holds the international launch of its all-new mid-size coupe, the RC, which arrives here early next year.

"We've got some fantastic sports cars coming," said Hanley.

To support the rapid expansion in models and sales, Lexus Australia will add another four dealerships within the next 12 months, bringing their number to 17 in the short-term.

But while the NX marks a new growth phase for Lexus, its sales won't all be incremental.

"Inevitably we'll lose some RX customers to NX," admits Hanley.

Specifically, Lexus expects the NX to eat into sales of the larger, entry-level RX 270, which could eventually be axed as a result.

Priced from about $69,000 ($8000 less than the previous entry-level RX 350), the RX 270 was introduced last year as the first front-wheel drive, four-cylinder, sub-$70,000 RX.

It was added to the RX range in the absence of a direct Lexus rival for smaller luxury SUVs including the Audi Q5 (from $62,600), which is one of Australia's most popular premium SUVs.

"I think there will be some leakage of RX sales, particularly the RX 270, which was brought in to fill a gap," Hanley stated.

"But the NX will bring a sales increase for us. We'll just have to have a close look and see how it [the RX 270] goes."

While Lexus has ruled out a smaller SUV in the short-term, the NX will compete with both compact SUVs like the Audi Q3 and BMW X1 (both priced from the $40,000s), as well as mid-sizers like the $60,000-plus Q5 and X3.

In this respect the NX is following its bigger stablemate's lead –the RX straddles both the Q5/X3 and Q7/X5 segments in terms of size and price.

The NX arrives first in 300h hybrid form before being joined by the NX 200t – the first turbocharged petrol model from Lexus – in the first quarter of 2015.

Both NX models will be available in front-wheel drive and AWD form, as well as three equipment grades, and both are expected to be priced from under $60,000.

The new IS sedan was Lexus' top-selling model last year with 2843 sales, followed by the RX (2188), the CT 200h hatch (847), large GS sedan (494), large ES sedan (187), large LX SUV (153) and the LS limousine (73).

So far this year sales of all Lexus models are down, except for the IS, which has posted a 19 per cent sales spike.

But with the IS notching up almost 1200 sales (400 more than the next best selling model, the RX) and the reintroduced ES sedan finding 285 homes, sales were up 5.5 per cent to May this year.