it will only protect you from car based deaths. and if you fall throug the ground, get out of driving mode. that should teleport you back to home then restart your save, that should un-bug that car.
EDIT: by car based deaths that excludes getting hit by a car when not in driving mode. this mod is mostly useless anyway since seatbelts are overpowered
EDIT 2: changed rating since mod is well, useless. mostly