heater box

Need some advice from people who have DIY'd AC evaps, heater cores, or had the heater box behind the dash out. I have an issue with my 2002 330i where the floor vents never really worked. I pulled the stereo to get a closer look today and found a previous owner of the car or horrible backwoods...

2000 328i - Hey gang, I had the strangest thing happen the other night. While driving home, my car started to overheat. It was about 50 degrees outside. I pulled over and because I just changed my thermostat, I had some coolant/water mix in the trunk. It had been driving fine for three...