Just give them a CyberTruck and have it Full Self Drive themselves into a pond.

The doors and window controls will short out and lock you in. Its not waterproof so water will be seeping in. The electronics will short out. The windows cannot be broken. The battery may explode/burn like thermite

Its a race between what will kill you faster: Drowning, Toxic Asphyxiation, Electrocution, or Burning.