The inexpensive (~$150) 120V plate type ozone generators can be useful to clean car interiors but beware of a few things:
The work much better in low humidity. If you have high humidity, they don't work nearly as well.
They all cheat on the ratings by doing stuff like force-flowing pure oxygen through the machine. Just realize the ratings are all fake.
They leave nitric acid which is an odorous gas that lingers a lot longer than ozone.
The UV type ozone generators are better for sure, but figure on paying 10X. Worth it if you can employ it in a regular service or for other tasks.
Ozone is only for unoccupied spaces. So the vehicle interior can be dosed/treated for anywhere from a few hours to several days when it is not otherwise used. Afterwards, you'll want to vent/air it out. The ozone has a very short half-life so it practically all gone in a day or two. If there is a lingering odor, it is probably nitric acid which is easier to vent/blow out because it won't break down as easily.
Ozone works because the 3rd O atom on the O3 molecule easily attaches to other (odor-causing) molecules and oxidizes them. It's the oxygen in bleach and peroxide that disinfects, sterilizes, kills mold, bacteria, mildew, and so on. Those O atoms also attach to dust/smoke/particulate molecules, weigh them down and cause them to fall and reside on surfaces instead of floating in the air.
No experience with ionizers.
