What pupose does 'coding to the car' serve? I bought a MK4 unit from ebay recently and managed to fit it with no problems. Halfords sell a very cheap extractor tool which made removal simple.

I am currently running it with a 2008-2 CD (not a DVD) and it's working fine. It's also upgraded to v31 firmware. ccfj1 has been a big help as well.

Am I missing something with not having it coded to the car?