Can a 2007 grand caravan without cabin air filter be converted to take a filter?
It’s hard to believe that there isn’t one on an 07. How familiar are you with cars and how did you determine that there isn’t one?
Doesn’t your owners manual show where the cabin filter is located and how to change it?
To answer your question, nothing is impossible for the right amount of work and money, but it MAY be difficult to redesign the area under the fresh air vent to accept a filter.