116K on my 2.8L 30V engine on my 99.5 B5.

Plugs were changed at 53K by the stealer. To my knowledge the wires and coil packs have never been changed.

Engine runs mostly smooth, although there is a slight fluctuation in the TAC when at idle.

Is it a good idea to replace all three together now, or should I just do plugs or wires?

I tend to lean on the preventative maintenance side of the fence, if that helps.

 

I changed all three on my car recently, the slight fluctuation is still there, but I think that's pretty normal (fluctuates about a tick or two). There was a ticking noise that went away after I changed the plugs though. Peace of mind. I didn't have any problems with the ignition coils- until I cracked it with a rubber mallet. But it sounds like you've got your mind made up, I mean if you've got the funds, I say go for it. And why not save on shipping and check out some of the other little things. Are your engine mounts leak-free, new vacuum lines, cabin and air filters?

 

Filters are good, have no idea about the vacuum lines. I had actually thought about doing the engine mounts. Are they easy to change?

 

engine mounts are pretty straight forward. Unfasten both engine mounts, raise engine, slip in the new one, lower and re-fasten (it might be a good idea to put it in lock-carrier position b/c of the radiator hoses, in which case you'd have to drain the coolant). The biggest problem you'll probably have is deciding where to put the jack (not that big of a problem). You want to lift the engine just enough, but you don't want to damage the transmission mating. Just be slow and steady when you're jacking it up. There's a diy floating around either this forum, audiworld, or 12v.org. Shouldn't be too hard to find.