Mine is wired even though I completely disagree with the assumption that wired will cure any lag problems over a properly setup wireless connection.
I ran in 2 other races in another series the same day we ran our last race. The other series is hosted in Europe, we ran two long races with full fields of cars and there were no issues with lag. I ran another race yesterday afternoon, again hosted in Europe, full field of GT300 cars on a short track and there were no lag issues. In our races, it's very seldom that there is a race without lag problems. The only difference is, in the other series we were having the same problems, every week someone was experiencing lag, it wasn't always the same person, and sometimes it was worse than others. We ended up solving it by not allowing mics in the room. Online racing actually requires very little bandwidth, using mikes to chat while racing uses a LOT more than the actual racing. I mentioned this a while back, but was told that it would ruin the social aspect of the race. I guess it comes down to, a choice between chatting or racing.
You can confirm this by checking your router logs after a race with and without mics. You may be shocked at how little bandwidth is actually required for racing.