In my personal opinion its only worth the hassle if you cant to import a "special" car that went out of production over 3.5 years ago and cant import due to our import age restriction.
For a "regular" car its a lot of hassle for a small saving. Would suggest that you pick something up from the local market preferably registered.
There are plenty of cars around that people are stuck with and you should be able to negotiate a good deal.
10,000 permits were used to purchase brand new vehicles which means that those users old vehicles were dumped into the market keeping the price of registered vehicle low compared to importing a used car.
Ex- Registered Nissan N16 - 1.7-1.8 million.
Price of the same model imported today would be approx 3.8 million
Although you would save on duty bringing in an older car, it would be more expensive than a registered vehicle in the local market.