Have you ever used a charcoal BBQ such as a Weber kettle? Do they have charcoal chicken shops where you live? Your car will end up smelling like that, only less meaty.
I'd be inclined to buy an old beater for this method. Even if a little extra work is required to prepare the car prior to ctb up i.e. duct taping over any doors or windows with perished rubber seals etc, it's not a big deal. There's no point in ruining a decent car when a cheap and nasty shitbox bought off some random from Facebook will do exactly the same job.