Agree with Sandra. We considered shipping our 3-yr-old Ford S-Max over here from the UK when we moved out here, but SOOOOOO glad we didn't, even though we ended up having to sell it for peanuts and having to buy another 3yr old vehicle (a Toyota Fortuna) for $31K. Everyone we spoke to on the subject, both before leaving and since arriving, has said similar things to Sandra: the process is a NIGHTMARE due to way too much red tape and the fact that no one does anything particularly quickly in Brunei! Haven't heard the 'corruption' line before, though. We were told a horror story about a colleague who had bought himself a new car in Japan and had attempted to have it shipped overe here; TWO YEARS later, he was still waiting for it to clear through customs :-/ Things like that just don't make the possible savings (from shipping a car in from abroad) worth it.
2nd hand cars here are vastly overpriced compared to the UK, and the concept of a service history is pretty much unheard of, so when you buy 2nd hand, you're entering a bit of a minefield. That being said, buying from fellow ex-pats who are leaving should be okay. Alternatively, if you know a bit about cars, you can pick up some really good bargains from the HSBC car auctions (repossessed cars mostly). Some have been in accidents, but some are in pristine condition, the owners just can't/don't want to have to pay the HP repayments anymore.
As Sandar says, if you buy an old banger (which will still probably cost you atleast $1000), the good news is you'll probably still sell it for that when you leave! Cars don't depreciate in value to zero like they do in the UK...they reach a baseline figure and then seem to stick at that, regardless of age, mileage or condition.
Good luck!