Some of these older luxury cars are tremendous bargains. Or, at least, they look like it in the classified adverts. There are a couple of reasons they're so cheap second-hand. The first is that people are (often rightly) scared of them going bang in an expensive way and requiring lots of pricey repairs. The second is called the funnel effect and happens when a luxury car like the 7-Series is bought brand-new usually by corporate customers. But, when the car is ready to be traded in a few years later, there simply isn't the volume of private buyers waiting for one to hit the market. So prices plummet. The same thing happens to Mercedes-Benzes, Audis and other luxury brands, too; it's not just a BMW thing.

Meantime, the rules of engagement are the same for any used car. The most important thing is not the distance the car has covered, but how well it's been maintained over the years. You need to see a stamped, up-to-date service handbook with no glaring gaps in the service history. Without that document, you could be buying an abused car that will let you down and empty your wallet.

The other thing to be a bit wary of in a 7-Series BMW of this vintage is the ex-hotel courtesy car. Back in the day, BMW had plenty of 7-Series to shift and a relative lack of takers, so the company offered them to hire-car and limousine taxi operators for about the same (leased) cost as a Holden Caprice. That's how so many of them wound up wearing a groove from the city to the airport.

A good, well maintained ex-hire car should be okay, but bear in mind a lot of them led pretty hard lives. That included a variety of drivers who may or may not have cared very much and long hours idling in gridlock traffic. Check the condition of the backseat to see whether it's been used often (does the wear in the back match that in the front?) and check the area around the rear bumper. This was often damaged as a million suitcases were loaded and unloaded from the boot.

Both the existing Genesis G90 (and its closely related Kia K9 sedan) are flagship models not available in Australia due to the tiny pool of buyers that swim in the upper-luxury segment dominated by the Mercedes-Benz S-Class.

The main stumbling block is probably the prohibitive cost of engineering these left-hand-drive market models for right-hand-drive. At over 5.2 metres long (and counting if you include the limo version), these are way too large for British roads, and the expected sales volumes from the rest of the right-hand-drive countries combined including Australia just doesn't make a viable business case for them.

Plus, big luxury SUVs are where the customers are heading, so a luxury crossover flagship from fledgling Genesis would make much more sense anyway. Sorry, but please don't hold your breath for a G90 in Australia any time soon.

However, the all-electric G80 – Genesis' big 5 Series-priced rival – is said to be heading Downunder inside the next 12 months. The EV limo is the brand’s first fully electric model and will have “more than 500km range” to take on the coming Mercedes-Benz EQS electric luxury flagship sedan.

Currently, the most expensive BMW is the 750Li, listed at $318,710. For more info on the latest model, check out our 7 Series pricing and specs page.