Be CAREFUL...Goo B Gone, while it is great stuff is VERY CAUSTIC...it will take the finish off your car as well as the road tar...I know because I did just that. You might try something less powerful such as a 50/50 mix isopropal alcohol and a very soft cloth, if that doesn't work increase the mix of alcohol until you have tried 100%. Make sure you rinse the CD afterword to remove any residue. You might also try Shine-O-La CD cleaner after you try the alcohol, the Shine-O-La should remove any residue, I've had good luck with this Shin-O-La stuff.
My2cents...
My2cents...