Bit surprised at that. In Comfort mode, I'd be hard pushed to describe the ride as anything other than incredibly smooth and stately. In Dynamic, it drops 20mm and the damping noticibly firms up, but it's still far, far removed from being even remotely harsh.
As far as bills, I've had an opposite experience to Rilot. The car has been faultess from day 1...a year and a half later I've paid £425 for servicing and £1100 for tyres and that's pretty much it. But as mentioned, I'm fairly sure if something did go wrong on a major component it could be crippling if you are running the car on a tight budget or without a warranty.
Have to agree with above, mines very soft in comfort mode, and stupidly soft in lift mode! Mines always in dynamic and its more than fine.
Biggest expense for mine has been rubber, total replacement is over 1k. The A8 has the best incar infotainment system I have seen so far, its really easy to use and its very feature rich without being illogical, everything seems to be where you'd expect to put it. Though, I'm one of the few that love the iDrive on the BMW's I rather have Audi's MMI its just easier to live with. The built in standard sound system is a marvel and the bose upgrade is nothing short of spectacular. The newer B&O upgrades are simply insane, with insane prices to match!
Running costs are fine, nothing is too expensive, yes, ok, if you're unlucky enough for an engine or a gearbox to die then its over 10k to replace (d3's), but if your looking at cars in the A8 class then i'm affraid they are all the same. There is and never will be a cheap gearbox/engine for an 80k car.
The 3.0TDI isnt really the car to be going for, they have the weakest gearbox of them all (multitronic), get the 4.0 or 4.2 diesel, or as its almost the same to run, get the 4.2 petrol, they are cheaper to buy, and with the cost of diesel right now theres not much in it.
Basically the 4.0 or 4.2 diesels are only a little more expensive to run than the 3.0 and much better to drive
the 4.2 petrol is only a little more expensive to run than the diesels and about the same to drive.
I think the only advantage's the 3.0 has is cost to buy and insurance.