GTA 5 Online Secret Location Deathmatch Trevors Meth Lab. To Access Trevors Meth Lab on GTA5 you can do it by playing this deathmatch or you can access Trevors Secret Meth Lab by climbing in the window on GTA 5 Online. Once In Trevors Meth Lab you can explore and have a bit of fun. There is loads f equipment in the Secret Trevors Metth Lab To Look At And See Hey guys in this video i am showcasing a deathmatch were you can play inside of Trevors Meth Lab from Campaign.