The equipment which <em>hostage negotiation team members</em> should carry in their car includes:
Writing materials.
The dossier of the aggressors (if already established)
Communication equipment
First aid.
<h3>What is Hostage Negotiation?</h3>
This refers to the discussion between armed aggressors and trained police officers in order to diffuse a hostile situation that involves the use of hostages.
Hence, we can see that some of the equipment which a hostage negotiation team would carry includes writing materials, communication equipment, first aid, etc.