Since finding evidence of mice in my glove compartment and also in the utility box under the hatch floor, I resolved to do my best to close all entrances, not only those to the air intake system, but also to the hatch area. There have been good posts on this site for most of the work and I used all this info to take things apart. Nowhere did I find a complete run down of everything in one place so I took some pictures as I worked this morning to record the process. The entire job pictured here took about 3 hours because it was my first time. My wife's Prius is next and I expect it will take me about 2 1/2 hours now that I am more familiar with taking things apart. I started with the hatch area where Patrick Wong had shown us that there are two openings which allow air to leave the car fast when you close the hatch. There are rubber flappers in the plastic frames of each hole which would be nothing for a mouse nose-push. To access these holes the floor and side trim panels need to be moved. Here is what my hatch area looked like when I peeled the side panels back. It looks awful doesn't it? What you will see is one opening behind the 12V battery on the passenger side which looks like this To obtain access to this opening it is necessary to remove the section of black plastic vent next to the battery. It is attached by two bolts and is not hard to remove. Once the black frame can be freely accessed, a screen was measured and bent to suit. The black flapper valves are in a plastic frame as you can see and are not straight but rather curved in a way which makes it more difficult to screen. I used 1/4" galvanized mesh and cut the shapes with tin snips. Here is the screen for the passenger side near the battery before it was installed Mine looked like this after it was installed with self tapping metal screws. When the vent piece was bolted back in position the screen can be seen peeking out above and behind the vent like this On the driver's side there is no vent and the frame is larger and oriented horizontally like this The frame is also irregular but a box-like frame was measured like this and installed like this Once the hatch area was put back together I moved to the front cowl area to tackle the many holes under the top grille and behind the water collection trough. I used an excellent post on "Prius heat efficiency mods" to help me (with lots of photos) to take the top cowl screen off, then remove the wiper assembly. After that was done the holes were all in the open and looked like this on the passenger's side and this on the driver's side. I used Ct. Ken V (thanks Ken) idea of making a cardboard template and fitting it in place before cutting the screens. They looked like this on the passenger's side (note the small screen on the drain hole) and like this on the driver's side. That colored mexican blanket above was covering the windshield to stop reflection from above That was it once all was re-assembed. One last thought about possible mice entrance points. This photo you will recognize as the passenger side quarter panel area. That black area is inside the quarter panel which is wide open to mice. It is the same on the opposite side of the car. Once they go down in there, is there a way for them to enter the behind dash area or the cabin? (Patrick Wong what say you?) I hope not or all this screening will have been a waste of time.