Hi Chris,
I dont have an answer to your specific problem but perhaps this could be an oppurtunity to upgrade your headunit?
You dont mention what your current headunit is but like alot of peeps on here, i have a RNS 510.
One of the features of the 510 is being able to play music from an SD card or even copy them onto the internal hard drive. No more faffing around with CD's!!!
If you go for a RCD510 (non satnav version) or the RNS 510 (satnav), i promise you, you wont regret it!
Hope this helps
Rich