Hey Alex-
Given that you'd primarly be using this car in the winter, why wouldn't you go w/ another Audi quattro? Did you have a really bad experience w/ the 90 or do you just really crave the BMW feel again? The one issue w/ a 97 540 might be the engine block. As you may know, many of the BMW V8s produced through 1997 were suseptible to excessive bore wear due to the high sulfur fuel in North American reacting w/ the Nikasil cylinder wall coating. Many people had their engine blocks replaced as a result-- you should check this out if you go w/ an early 540-- have a dealership perform a "leakdown test". Both of the cars you're interested are certainly more of the higher performance models- and could be more likely to have been driven hard, and are more expensive to fix. Of course, I don't know what your financial situation is-- but again given that this is a winter only car-- might it be better to get a lesser model? An e36 328 or 25 perhaps?
Given that you'd primarly be using this car in the winter, why wouldn't you go w/ another Audi quattro? Did you have a really bad experience w/ the 90 or do you just really crave the BMW feel again? The one issue w/ a 97 540 might be the engine block. As you may know, many of the BMW V8s produced through 1997 were suseptible to excessive bore wear due to the high sulfur fuel in North American reacting w/ the Nikasil cylinder wall coating. Many people had their engine blocks replaced as a result-- you should check this out if you go w/ an early 540-- have a dealership perform a "leakdown test". Both of the cars you're interested are certainly more of the higher performance models- and could be more likely to have been driven hard, and are more expensive to fix. Of course, I don't know what your financial situation is-- but again given that this is a winter only car-- might it be better to get a lesser model? An e36 328 or 25 perhaps?