Labs_underpass_p.upk May 2026

Move your renamed custom map into the mods folder.

Ultimate Guide to Custom Maps in Rocket League: Mastering Labs_Underpass_P.upk

You don’t need to swap files between playing online and playing offline.

Create a backup of the original Labs_Underpass_P.upk to avoid losing the default map.

No, you can ignore the universal Mods.upk file for this method.