None.
This is a very comfortable car particularly over long distances.
The interior is very easy to live with especially if you have children.
The instruments are very simple and all information is displayed in a logical and easily read format.
The performance is very good and the transmission shifts up easily, however, use the tiptronic style shifter for fast changes.
Fuel economy is good but the engine is still tight for really good economy.
The suspension soaks up bumps really well and the handling is great for this type of vehicle. The steering suffers from some vagueness either side of centre but as speeds increase this does lessen. The brakes are excellent.
The headlights are poor so if you can replace them with H1 equivalent or better at A$28.
The stereo in the LS model is also a letdown. The speakers themselves are good but the head unit is a single CD/MP3 AM FM unit which should sound good for a standard system but does not. So if you can replace it with something to your liking.
However, these are the only two faults that I can find. The car itself is a great drive and a great family car.
I live in United Arab Emirates. I bought a used 2006 Grandis (Petrol) in March 2009. Although I like the car but the parts are extremely expensive which I didn't check before buying. The car's acceleration considerably reduces on switching the A/C on.