Coming from a very satisfied BMW owner; a 7-series is NOT the way to go if you want trouble-free motoring. These cars break almost as often as a Mercedes S-Class. They are decent overall, but you will be in the garage often. Definitely avoid Audis if you do not want to be inconvenienced. I love Audis, but cannot afford to own one right now.
That said, if you want a reliable car buy a six-cylinder 5-series or any 3-series. I have a 3-series and it is by far the easiest car I have ever lived with. A 5-series is basically a larger 3-series because it is not much more complex, just roomier.
No doubt the 740 is hard to maintain money wise. It definitely is not an old farts car. I feel and so do many others that it was the last of the 7 series made that is a REAL BMW. The new age look on the 2002 onward productions have simply spoiled the beamers edgy yet elegant looks. I own a 01 740ia... it's the most amazing car ever. Feels like a dream. She's high maintenance~!
The 7 was originally a $100,000 car. What do you expect? The parts and service are still based on a car that expensive. I always think it's so funny when young kids buy a car like that trying to impress, then are surprised when the repair bill comes. These people are almost always previous japanese car owners. You're not buying a Honda. It's a BMW. If you want to be a little more realistic, buy a 3.
I would have to agree with all the previous statements. I have 1999 BMW 740iL that I bought used back in 2004, and in 2009 the problems started rearing their ugly head. The car runs and drives like a champ, but with the $800 water pump replacement, the $380 right rear window modulator replacement, the $840 calipers replacement, the $230 battery replacement, the $260 cam positioning sensor replacement, and so on and so-forth, I'm seriously considering buying something else, and parking the BMW.
I have broken everything on the interior that are too many to list at this time. Great driving experience, but only when you are not coming out the pocket to keep it drivable.