From the sounds of things, you need a vehicle that can accommodate the wheelchair as an actual seat in the car rather than having the chair folded and stored for the journey. With that in mind, a van or people-mover is by far the best best bet and the news is good, because there are plenty of choices. For a while there, people were converting Ford Falcon station-wagons for this task, but since the Falcon is no longer made, vans have become the new default vehicle to convert. Which makes plenty of sense.

There are specialist firms around that will carry out whatever conversion you require and tailor-make the ramps, lock-down points and grab-rails you need to make it work for you. Switched on companies will sit down with you and discuss your precise requirements and engineer something bespoke if necessary.

At the moment, the list of car choices is pretty long and includes the new Hyundai Staria, VW Caddy, LDV G10, VW Caravelle, Renault Kangoo, Renault Trafic, Hyundai iLoad, Mercedes-Benz V-Class, Toyota HiAce and, in case you need something really big, even the Toyota Coaster. Some of these companies are also registered as NDIS suppliers.

But don’t rule out a second-hand vehicle, either. There are websites around listing used wheelchair-accessible cars for sale. Some will be ex-taxis, but others can be relatively low-kilometre cars that might just have the exact layout you were looking for.

They're usually calculated on the price of the car as purchased, so if you bought it having been converted then that is the price that would be used. If you bought it and had it registered before it was converted then you would pay the stamp duties on the price before conversion.

There are things that could cause abnormally high fuel consumption, like a faulty oxygen sensor, faulty ECU, blocked exhaust, but the dealer mechanics found no such problems when they checked your car. The fuel consumption figures quoted by carmakers is the result from a laboratory test under controlled conditions, it's meant to provide a means of comparing makes and models, rather than give you a real life figure that you could expect to get from your car. That said, the difference between the test result and your car's consumption is too much. I would sit down with the dealer and have them explain the reasons for the difference.