a/c smell

It seems like it's finally time to spray some Lysol into my vents as the smell is really moldy when I use my AC. However, I'm truly puzzled by the location of the outside vents. Is this the only area from where air gets into the cabin? It's weird as on other cards there were rather large areas...

I have a 2012 Hyundai Genesis 3.8 6-speed Track and I am extremely aggravated on this issue. I went in to have a standard radiator flush and fill service from a reputable/local shop. Approximately 1 day and ½ later I began noticing an odor possibly a burning smell coming from my driver’s side...