possibly true.....if you dont have AC i think the filter could fall into an abyss...i dont have AC and lost the filter in an abyss, but got it back, freaked out, and dont run a filter,,,the honda 2015 fit has a filter and drove it last week and smells a little funky,,need to remember to change filter..your dads car didn't have a filet and hes doing fine(ok his memory going a bit)