Wow! A new car that smells like a deli. I think that would drive me crazy not being able to taste the goodies. I'd be going crazy getting hungry all the time. But I can reassure you, my son would drive you worse nuts with the gas he passes...and he thinks it'* funny.
Seriously, why would the headliner of one series of car "smell bad"? Gotta be the material or glues they're using not being compatible. I work with trains. One of the operating ends in one of our Light Rail Vehicles was fine until the fall when the heaters needed to be turned on. Then, every motorman who drove it asked for it to be changed out at the end of the line. Reason? The cab smelled like stale urine when the heaters were on. Warranty from SIEMENS was excellent. Train went out of service for several months while another cab was installed. Old cab was analyzed and found that the fibreglass hardners were at fault. Mixed in wrong concentrations with an "unknown" additive.
I would take the car back and get another dealer loaner of another model till they fix it. No way I'd buy a new car and put up with that kind of nonsense. Good luck, and hope the solution comes your way soon.