In most vehicles, when pointing to NPC, command option shows Recruit / Remove from group.

But inside Ural (Soviet. Fia) and US M998 vehicles, option is no longer showed.
Other vehicles do not have this issue (few are more picky, where exactly to look at NPC while recruiting).

How to reproduce:
1. Recruit NPC
2. Get in one of mentioned vehicles
3. Order NPC to get in
4. Look at the NPC and open Command wheel