Gas can would leave the wrong kind of residue and would exonerate the Tesla as a victim of a false flag eco terror attack. Use the inherent problems with lithium batteries to start a fire. A lithium fire is one of the types of fire that firemen will straight up avoid until the dedicated response unit arrives. A lithium fire will not leave survivors. It starts with an explosion and gets worse from there. Given enough time this happen naturally in that tunnel; it doesn't need help.