I had created another thread, for using the cabin of a car, to fill it with gas (like helium, nitrogen, etc) for CTB. This could allow people to CTB, in a peaceful way, out of any place where they can be found and then resuscitated. This is possible if you have to flee your home, if people are likely to prevent you from CTB, if you cannot afford a hotel (a hotel room requires a mask, a bag, etc., for CTB , difficult to bring back this material without being seen), or if you want to admire a landscape one last time before CTB.
There have already been CTBs with the exhaust of a car brought back into the passenger compartment.
My idea was to use gas cylinders, such as helium or nitrogen, which would be enough to fill the passenger compartment of the car, it would suffice to find a way to evacuate the oxygen from the car and to close the breakdowns.