I just stumbled across this thread. Interestingly, this is one of the methods on my short list of CTB. I have an old car, rusty and rotting apart, that I have held onto for heading out just this way. It runs absolutely fine. It has had the catalytic convertor removed and replaced by a piece of straight exhaust pipe. The smog control pump on the engine can be easily removed, too, if that would be beneficial to CO production. When my time comes, if this is the method I choose, I would attach a piece of bendable exhaust pipe to the tailpipe and route it to sealed piece of sheet metal that I would fabricate to take the place of one of the door windows. I would seal any potential air openings that I could around the doors, the duct work, etc. I have also been contemplating building an "enclosure" around the vehicle in my garage consisting of a wooden frame covered in plastic sheeting.
The questions I have yet to answer are:
(1) How hot can I expect it to get inside the vehicle from the hot exhaust depositing into the cabin of the vehicle? Unbearable?
(2) How bad is CO poisoning? What "negative" effects can I expect to experience before passing out from the CO?
(3) If I take something to pass out, a bunch of sleeping pills or whatever, in order to have a more peaceful experience with the CO, and my respiration slows, will I still be able to breath in enough CO to get the job done even though I am passed out? I want to avoid the inevitable headache, too. I'd probably start the car when I feel like I'm ready to drift off from the sleeping pills.
This vehicle is already a "polluter". It's not like the new cars of today. I'm sure the amount of CO produced from it's engine is not a problem. What do you all think of this plan, thus far? Critiques are most welcome.