USB Aux Flush-Mount Block Switch Adaptor for RNS/RCD Radios 300 310 315 510 : Amazon.de: Electronics & Photo
iPod CD changer adapter, VW iPod, Apple Carplay, Android Auto Music Link are available at xCarLink – the best place for all of your iPod car linking needs.
RCD510 RNS315 RCD310 Car USB AUX data Adapter Switch Button Cable wiri — Vagpartsgo
RNS 510 USB inputs | VW T6 Transporter Forum
Volkswagen RCD 510+ USB Head Unit pinout diagram @ pinoutguide.com