My car has a very slight, but noticeable wobble at around 70 mph. It's odd, 60 is fine, 90 is fine, it's always around 70mph. I've had the tires balanced, and they only have about 5k miles on them so wear isn't the issue. Keeping on top of tire pressure helps a bit, but even when the tires are right on spec it still shows up (albeit very, very slightly at that point). It really is quite mild, you can feel it a bit in the wheel but it's not like a shake/shudder, so I live with it. Next time I take it in for service i'll inquire more about it.
E88 N54 Alpinweiss/Coral Red/Motiv HTA 3586r Tial .82AR/Other stuff...652WHP
F30 N55 XDrive EBII