F1 Lookup Format Restrictions

One of our users would like to have an access right added to the system to enable editing the F1 lookup list or restrict editing your F1 lookup list.

In this situation, this company wants to create a ‘Read Only’ User for one of their customers to see their own vehicles history. We would setup their F1 lookup list to view their department 's vehicles, and restrict them to all other modules in RTA.
Thoughts?