PurpleProject

Collect Street Sentinel XS cars or buy them from Southern San Andreas website.
Fill your Facility with 6 regular (stock) Sentinel XS cars.
Make sure you have 1 fully upgraded HSW Sentinel XS in the Facility as well.
Before starting the glitch, identify a crew member you can join to help avoid session switching mid-glitch.

Requirements​

Facility with Avenger parked inside
Free-Aim targeting mode enabled
One HSW-upgraded Sentinel XS and at least one stock Sentinel XS
Controller for timing-based menu maneuvers

Duplication Phase (Repeat for each car)​

Get into your HSW Sentinel XS inside your Facility.
Drive it into the Avenger’s hold and exit the vehicle.
Enter the Avenger cockpit and pause timing line-up:
Hold left on D-Pad to enter hold, wait for stand-up animation.
Open Pause Menu → Online → Crews → Leaderboard → pick a crew → view member.
Join a crew member’s session; accept the first alert, back out of the second.
While still in Pause, go to Manage Characters (don’t confirm), then quickly shift to Safety & Alerts by holding the pause button + the Safety/Alerts button.
Release both buttons—to land into Safety & Alerts menu.
Exit that menu, immediately open Interaction Menu (you should now be standing outside the Avenger).
With Interaction Menu open, approach a stock Sentinel XS in your hold.
Enter the stock Sentinel, and as it starts, close Interaction Menu and drive out simultaneously.
You’ll load back into the Avenger—but the HSW Sentinel XS remains inside.
Enter the vehicle and make any minor modification (e.g., plate color) to finalize the dupe.
Both the HSW sentinel and its dupe will now sit in your Facility. Dupe will be invisible until session switch.