So I can't believe it's taken me this long to figure out, but I think I finally know where the problem is coming from. A while back I had an incident where a shop had taken my Enkei PF01's off the car and thrown my Rays on forgetting that the right front PF01 left it's hubcentric ring on the hub. They bolted up the wheel and drove the car, and when they realized the ring was still on and the car was driving funny they took it back in and discovered the problem. I think the wheel bolting up over the ring and onto the hub caused some damage to both the hub and the inside of the stock Rays wheel. That's why I get the problem slightly when the PF01 are on (those wheels aren't damaged, but the hub may be slightly) but when the Rays are back on the shudder becomes MUCH worse. I took some pics, it's hard to see but the inside of the wheel that sits on the hub is nicked/bent up pretty good in spots. Either way, I ordered a new hub and we will see what happens.