There are three buttons-one to pop the trunk, one to pop the gas tank, and the last one? It has a picture of the car and three lines like radio waves. Any ideas?! Thanks!

rear window defroster?

i think this opens/closes the outside air vents(they pull fresh air in when open and recirculates the air inside the cabin when closed hope that was right check your manual if you have it

It should beInterior Monitoring button.This button forms part of the interior checks for change in air movement in the car when locked with key and the SAFE red light on the door is on/blinking.Incse the interiormonitori senses change in air movement in the interior, the alarm is activated.I hope this helps.