For auditing purpose was asked to collect [local]\Administrators group members on every machines.
I created a script (Get-LocalAdministratorsMember.ps1) for that and deployed via GPO to all clients. This script do not require admin rights, but a share where every users can write.
When you have all the reports of your clients on selected share, run Export-LocalAdministratorsReport.ps1 script for generate a CSV file for reporting.
Follow the Synopsis for change the settings.