I had something similar to this happen on my '03. Weird thing about mine was that it was only the driver side
The very outside edge was wearing badly. I had my shop look at it and one of the guys thought it could be toe, but that would affect both front tires, not just one. Air pressure was at around 32 in front driver side, and 30 on passengers side. With that I would think that the passenger side would show wear on the outside before my side did.
I got the car lowered a week or so after I noticed the tread wear, so I put c/c plates on as well, and got it aligned.
Later I got 2 Nitto 555's put on the back, so I just kept my 2 best tires and put them on the front.
If anyone is in the market for new tires I definately recommend the 555's