Anyone ever have a musty basement smell in the Honda CRV?

It sounds like you may be describing the symptoms of either floor mats that have become water soaked and are mildewing, or a plugged air conditioner condensation drain.For the mats: do a manual check of the mats both front and rear to determine if any of them feel waterlogged - if so, remove them and dry them out, and at the same time check to see if there is any place that water may be entering the passenger cabin (loose door seals - rusted through hole in the floor pan -etc). For the A/C drain: slip off the condensate drain hose - located in the lower right hand forward corner of the housing and insert a stiff (but flexible) wire in the housing and down the tube to free any blockage and allow the accumulated water to drain out.