Adding (10th Dec 08):
I have completed 36000 with my Duo. Now I feel the difference of power between petrol & LPG. I have switched to new wider JK tyres (which comes with WagonR Vxi). Im getting average of 10 kmpl in LPG local.
When I went on long drive Delhi Amritsar I got an average of 13.3 kmpl of LPG and 17 kmpl of petrol. So I feel it doesnt make much difference in savings, while one has to spend about Rs. 35000 (incl discount) and compromise with boot and little more maintenance.
Earlier:
I bought wagonR duo in September 06.
Im getting an average of 11.2-12.0 kmpl on LPG (mostly local and 50% ac on). A full tank of LPG (around 22 Litres) runs 235 - 260 km. But people driving same car told me, they are getting 13 (ac local) - 15.5 kmpl (non ac).
The boot space is the main disadvantage. I havnt installed rear speakers because of this.
Apart from gear shifting (reverse and 2nd/3rd), the driving is comfortable upto 100 kmph.
There is negligible power difference in LPG (without ac & upto two peoples).
Interiors are average. The Ac is powerful enough. The Brakes are good. Leg space is sufficient.
It doesnt feel conjusted, even if five (normal weight) people are travelling.
Maruti should have provided the option of Power window and internally adjustable Rear view Mirrors.
This Car is best suited for small family, who resides in NCR region, where LPG is available easily.
Overall, Im satisfied with my car.