I usually change my cabin filter at about 20,000 but really they have never been that bad. It just depends on the climate. More dust will get it dirtier faster. I don’t know anymore what the recommendations are since they just come up on the computer as Service I, II etc. If the book doesn’t say anything, I’d at least have a look at 15-20K.
The reason I inspect T every oil change is that the folks changing the oil will check anyway, and I want to be prepared for them. If I know the condition beforehand, I know what to expect when they show me my filter. I also can change it if needed, and avoid the extra charge for them to do it. And I know if they show me a dirty filter they keep around to hoodwink customers. Not that I expect them to mess with me, but it is worth finding out as early as possible. If they do. Trust but verify!
In my case I spend most of my time with the roof and windows wide open as long as the temperature is above 50F. Even if it isn’t, I’ll often tilt the sunroof to get airflow. A cabin filter would seem about as useful for me as an appendix.
@Juanita
Your car doesn’t have a cabin air filter
I used to own a 1997 Protege, and I know that car in and out