Your complaint of wetness is all relative. What do you mean? What shows that it is muggy?
Muggy can be a smell, or wetness can mean that the windows fog up every time you close the windows? There is a great range...
If the windows are fogged:
Take off the floor mats and check for wet spots along the bottom of the windows, windshield, and doors.
Check all the carpets for wet areas. The highest part of the carpet will be more wet.
If it is a warm day (65+) drive the car with all windows open,
make sure you park the car in the hot sun so that the water will evaporate.
check the trunk for wet carpeting
check for rust stains in the car all around
Make sure that all the windows and doors close correctly and do not leak.
If you did not find wet areas, run the air conditioner every time you drive and see if the insides keep on staying wet... Then you know you have a leak..
Last edited by powersurge
on Thu Apr 02, 2020 6:01 am, edited 1 time in total.