Easy to use and was helpful
We recently got a plugged up condensor that backed water up in my wifes car, which sat with the water in it and got a nasty smell.  Used another cleaner from Autozone that did nothing.  Ordered this cleaner and it seemed to work a lot better.  Did not completely take the smell away and repeated applications were necessary.  This is more so due to the extent of our issue, so if you have a really, really bad smell from something like water/mold issues, don't expect this to be a cure all.  You may need the direct cleaner with the tube to get it down your air vents.  But for a light smell issue, I think this could work.  Very easy to use and a great first option.
Rating: 4 stars