These CDR's have limited readability as well as writeability. In other words, don't expect to be able to pop it into your car stereo and have it play.
OT: there are now several recordable disc prototypes in the 20 to 50 GB range, and I was reading about these as long as three years ago. These also have transfer rates in excess of the fastest (yes, faster than Ultra-Wide-and-Special-and-Fast SCSI, etc.) hard drives. C'mon, tech sector, get off your duffs and release these!