The manual says it has a cd changer port. the radio is made by blaupunkt. you can get a blaupunkt ipod cable. I looked into it before but still havn't gotten around to doing it. Got this email but never called the number:
"For information on using the Blaupunkt iPod cable to connect your iPod video to your Opel factory-fitted radio, contact the Blaupunkt technical helpline on 01895 838 880. They will be pleased to assist you.
http://www.bluespot.co.uk/stock/ipod_cable.asp
The iPod adaptor is in stock for immediate dispatch.
Regards.....Customer Service
sales@bluespot.co.uk."
If you have found another solution please let me know.