you can buy ones that you need to buy the adaptors for but they are normally alot more expensive like so its pointless using them or get a dvd one from ebay they sometimes come with the adaptors
The adapters aren't that expensive at all. Think I got mine for about £10.
ive seen people post up selling aftermarket head units from Mk3 that include the adapter.
Send a PM to MT Audio if he's still around ?
Pretty much a genius when it comes to setting up audio adaptor thingies.