This is certainly getting stranger by the minute! Would you happen to have any explanation or theory as to why replacement of the front rotors & pads would cause such a vibration problem with the rear rotors? They seem to have no connection whatsoever considering that they are on opposite ends of the car. Also, these cut out shims--Volvo service dept. sell these as a kit? How much are they roughly and how much would it cost to get them installed?

Thanks again everybody.