Hi, I have a problem while playing LSPDFR, it's normal for me that the police vehicles called by the backup menu or the vehicles created by the scripts/callouts disappear when I'm not looking where they are for few seconds, so the peds stay but the cars not.

Is there any mod that make them persistent like my own vehicle, or is there any other way to solve this?

Thank you.

This is a GTA V feature. You can search for a persistence mod to counter-act this, but keep in mind Rockstar made the game like so to clear up videomemory.

Yes, there a persistence mod, you should use that search bar on the top right :)