Something that’s always bugged me about Twilight: 2000’s vehicle combat is the relative lack of anything meaningful for the person in the vehicle commander’s seat to do. Sure, many of them have their own pintle-mounted MGs, but there’s no command function. This recently came up in a Kaserne on the Borderlands session and my table had a brief discussion about it. Here’s what we came up with:

Vehicle Command: As a slow action, the vehicle commander may coordinate the actions of his vehicle's crew.  Make a Command check.  With success, this counts as help (Player's Guide, p. 46) for each other crew member's actions this turn.

Timing wasn’t an issue because of our house rules on initiative. The table agreed that the commander should act first to determine success or failure on granting the bonus.

In the interest of balance, we restricted the benefit to actual crew positions, not passengers. There was some debate about whether human cargo using firing ports should benefit, but I felt that was excessive. If you want an in-game rationale, assume that only the actual crew seats have jacks for the vehicle’s intercom.

This seemed to work well as implemented. The commander’s player felt his XP investment in Command was being rewarded, and the gunner appreciated the extra +1 to offset penalties. The driver was a NPC, so he didn’t have opinions, but the bonus was there when needed.