Dead rat in my aircon!

I couldn’t recall when my aircon smelled like dead rat; but it was something too much for me to bear further.  So, I did the following:

1. Threw a bottle of air freshener in the cabin. 
2. Installed a DIY aircon filter made from the filter material for my kitchen gas hopper. DIY steps can be found in the civicfd-sg forum.
3. Wired a car ioniser bought from Autobacs. It was a small 30-minute DIY project. I installed it in the empty compartment right in front of the shift stick. It was partially hidden. In the night, it emits a bluish glow lighting up the compartment. Picture below.
   

So far so good. No more dead rats.