application/vnd.viwi.v1.4.2+json

[1] Volkswagen Infotainment Web Interface protocol definition (2016-12-24 01:55:51 +09:00) <https://www.w3.org/Submission/2016/SUBM-viwi-protocol-20161213/>

Accept: application/vnd.viwi.v<MAJOR>.<MINOR>.<PATCH>+json
To access the API version 1.4.2 the Accept Header would be:
Accept: application/vnd.viwi.v1.4.2+json