ok here's a better illustration of whats going on with my rears.
notice the tread blocks are all even except for the center tread block (it is concentric btw)
http://img.photobucket.com/albums/v433/1z4u2c/tyre.jpg

 

Do you have an actual pic of your tire? How's the camber and the tow on the suspension?

 

if the middle is wearing out more than the edges, it might be overinflated..

 

http://img.photobucket.com/albums/v433/1z4u2c/tires.jpg

 

Are you running after market rims? What width is the rim? What is the tire size? Rim too wide for the tire?

 

That's what I'm thinking...

 

+2

 

That looks like the Pilot A/S and I have the same problem. However, I run my tires at 30 PSI on my OEM 17". This the 2nd set for me that show signs of overinflation.

 

overinflated +3

 

+4

 

I had the same problem with Pilot Sports A/S with 35 psi so I replace the rear with Kuhmo ASX 30 psi and now slightly under inflat so I believe its the tire itself that doesnt have enough rubber in the middle to support the pressure.