We have a Merc, a BMW and the S8 at home and I must say I really don't agree that the BMW interior is not excellent - the Audi is the better finish by a smidgeon to my beloved X5 4.8iS, which has soft special order leather seats and about 20x the number of toys of the Audi, including a much-treasured Webasto parking heater, a rarity on their petrol models and a pricey optional extra when new. Interior finish is comfortable and classy as I would expect on a car that cost almost as much as the S8 when new. I absolutely love driving it and the BMW V8 which I think is an Alpina derivative is awesome.
The two Mercs at home - an A class and an original (best!) shape SLK by comparison to the BMW and Audi are pretty boring, plasticky and crappy,the leather nowhere near the quality of the other two, but the SLK has redeeming features in that its such a happy car to drive, always brings a smile!! The A class is just a runaround mostly for our ancient Border Collie to take trips out, as its easier for her to heave into the flattened boot (have put the rear seat up) but its boring as hell not to mention slooooooow and I can't quite see why anyone would pay nearly £20K for them new nowadays!!!
I'd have another BMW anyday - great dealer service compared to the gitz at Audi and Merc dealers! My X5 is only main dealer serviced and repaired and I've continued the BMW warranty.
Given the dramas in getting these 8s repaired and serviced, I might just throw in the towel at the next major problem and stay with BMW........have owned the same S8 since 2004 and hope she'll be ok for a few years yet and have yet to see the same interior quality in ANY car. My old Range Rover interior was utter poo compared to the Audis as well, and that also wasn't a cheap car new.