Hello everyone I have a 2008 base model aveo with 145000km. Recently all the interior windows are frosting up so much they have to be scraped from the inside. The car still produces good heat but has to be run on full defrost with the fan on high to keep them almost clear. Front windshield drivers and passenger windows will clear but rear windows don't ever. Checked the coolant today and it was almost completely out, I'm unsure of how long it was empty for. Refilled the coolant and checked the thermostat for visible leaks but found none. Will park on news papers tonight looking for any leaks. Any ideas on what to check next. Thank you!