I've seen an 05 Range Rover L322 4.4V8 petrol with an lpg kit on it at a very good price and I'm tempted to go and have a look.
Trouble is... I know that there is no such thing as a cheap Range Rover!
Especially not with the BMW lump in it... Neglect causes timing chain issues, which will render the lump scrap... The price will tell you how imminent this is. Assuming of course the the wiring allows the engine to run long enough to break...
Or the oil in the plug wells catches fire......
To be fair - it's not like the Omega doesn't share a lot of these failures (besides chain because.. belt, but neglecting that will still lunch the engine), though. Oil in the plug wells, coolant/oil leaks in the middle of the Vee.
Having had a few other cars too, it seems like most of these failures are common to all modern cars - especially rocker cover gaskets..