Zorbx. It's non-toxic and fragrance-free. Get it at Amazon or zorbx.com
I bought a used car one time that had been driven by a smoker. He tried to do me a favor by taking it to a car wash and having it dipped in a vat of cherry car scent- but you could still smell the smoke underneath. It made me too sick to drive it.
We tried to get rid of that cherry smell with chlorine bombs, enzymatic cleaners, even paid a detailer $200 for an overnight ozone treatment. Nothing worked except Zorbx. Sprayed it into the upholstery, headliner, carpet, dash, doors, in the vents... In five minutes the fragrance and smoke smells were GONE. Left no fragrance behind. Saved my car. Best. Stuff. Ever.