Hey folks,
We unfortunately had a delay with the implementation of the update which will add Chems and Vehicles to the codex. Apparently, each vehicle has to be individually marked (or at least important representations of each one) for it to unlock when approached. That said, it is being worked on now and should be out this week. We'll change this post in lieu of its release.
PC (Bethesda.net) | https://bethesda.net/en/mods/fallout4/mod-detail/4042260
PC (Nexus) | https://www.nexusmods.com/fallout4/mods/27629/
XBOX ONE | https://bethesda.net/en/mods/fallout4/mod-detail/4040890