Another option that I use is an fm transmitter. You load your mp3's on a usb flash drive and attach it to the transmitter. Plug it in the cigarette lighter and it plays thru your bikes fm radio. When you want to add or delete tracks, just do it thru your pc. Works great and you can change your music anytime you want without reburning another cd. Anybody interested, let me know. Can get them for about $35 including the flash drive.
As for the loudness issue, a program called Audacity works good.The maximum loudness can be set and all your music will be the same volume. No moreconstantly adjusting the volume for every song.