Dean,
Method depends on source of odor.
If milk, urine, vomit, etc. in carpets, seats or trunk area, soil extractor is used to completely remove material. Then use air freshener like Ozium. Interior detail is like $59.
If odor is cigarette or cigar smoke treat with ozone generator. Treatment usually takes 15 minutes or so then ventilate for 5 or 10 minutes before getting in vehicle. Price varies from $25 to $50.
Careful though, too much exposure to high concentrations of ozone will degrade rubber seals and carpet and upholstery dyes and weaken fabrics.
If bacteria are growing in AC/heater duct work, there are biological agents that can be introduced.
One method is to use a fogger or smoke bomb (can) while running A/C. Fog takes as long as ozone cost is about the same.
Another method requires drilling small hole in A/C heater air handler and using aerosol can to inject agent. This takes about two hours, $25 per can.
