VW RNS 510 help please

[tdi sport]

Any help or guidance to this appreciated, many thanks in advance.

I purchased a 2010 RNS 510 unit for my now sold B6 Passat back in 2010, not new.
All fine no problems, till I sold the car last year. I took the 510 out to put the old radio CD unit back in, again no problems.
I thought I had the 510 code as I'm normally s##t hot with stuff like that.
I had recently moved house and couldn't find it with all the car literature etc.
Now the car had gone so no facility to plug it in now, I powered the 510 from a car battery to check the code I was given (twice by different providers to be sure) and code didn't work??
Is this because the can-bus system etc is not present or is something else going on?

[Vikingraider]

I'd guess someone changed the code at some point. If that's the case it'll need decoding on the bench rather than by serial number. What's your location?

[tdi sport]

I'd guess someone changed the code at some point. If that's the case it'll need decoding on the bench rather than by serial number. What's your location?

I'm near King's Lynn, Norfolk

[Vikingraider]

Too far away from me to drop in and have it done then really. You could post it but it gets expensive both ways.

Are you selling it?

[tdi sport]

Too far away from me to drop in and have it done then really. You could post it but it gets expensive both ways.

Are you selling it?

Yes am looking to sell it

[Vikingraider]

How much you looking for?