Originally Posted by *********
On an 06 I would probably replace all coils too.....just for peace of mind.
The benefit of coil overs is that when you have a problem like this you can replace just the single coil. The downside is they are generally more expensive if you have to replace the whole set in comparison to a traditional coil pack. However, just because his coils are OE on a 2006 doesn't suggest he should replace the lot. That would honestly be a huge waste of money, albeit you can find them fairly inexpensive some places. For example here
you can get them for my e90 sedan for 29.99 a piece. Like the old saying goes, don't fix it if it ain't broke.