Hi!
You pay €86 for a GRA if you haven't done enough research beforehand. That's what happened to me

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The most expensive part of the GRA retrofit kit is actually the installation, especially if you have it done by a VAG workshop. (approximately €50-100).
Das Geld habe ich mir gespart und das Ding selber ein gebaut. War zwar ziemlich schwierig ( Passat Bj.´98 ) aber nun funktionierts und ich bin sehr zufrieden damit. Nice! / That's great! / Wonderful!
The activation made the workshop service at VAG free of charge. '

' Service.
Best regards, Björn.