<br>Researched and found the following: Hans Sogell stated that the SC900 / SC901 are both state of the art system, build for incredible sound clarity. When you buy a CDR, you loose alot of the clarity. The sound is not fine and does not utilize the capabilities of the SC90X system. Because of the loss of the precise sound, the engineers, in their software programmed the unit to be able to detect a true cd by the "lag" time between files. Reduced lag time means that the owner is using a CDR. Some c70 are running units with upgrades, thus bypassing the programmed mod. This mods can be uploaded at your local Volvo dealer. Standard c70's are programmed to reject CDrs.