Brian,
The codes are usually stored at the first dealer who sold the car. you should be able to track that down from the original documents. Otherwise it looks impossible right now to break the code without messing with the inside.
I have myself a laguna estate from 2001 and I changed the stereo to a panasonic. At the end it does not matter which stereo you buy since the stereo can be hidden with the central console cover.
hope this helps,
Sam.
Sam, September 2007
