Introduction: Prius Gen4 Rear Wheel Acoustic Isolation

This is an easy photo log of my weekend work.

Step 1: Door Lower Piece Off

You have to screw off 2 x 10mm bolts that hold the hooks, then pull upward to detach the piece.

Step 2: Left Side Panel Off

there are 2 x bolts for hooks, and 2 screws under small plastic covers.

the plastic plugs are 2 (white colors) on the side, 3 on the top (red)

Step 3: Tricky Part

Need to get the safe belt out, it's easy to find. remember when you put them back, the small opening needs to plug into the panel perfectly, or you will not able to assemble, beware of the air-bags set on the roof. we are working near that area!

Step 4: My Isolation Panel (from Amazon)

Here is the product i put in my car, come with 17 sheets. pretty enough for this job, if you want it for passengers doors too, you may buy another set, here is the amazon link:

(PD: mine is 170 mil x 18 sqft, is not available, what I found is 150 mil, just similar performance)

Step 5: Start to Stick

the left part is under a plastic cover which you do not need take off, it's way more complicated as you need to take off the seat. i just rise it up and stick to access it, this part in my mind is the most important part of the job, I believe the mayor road noise is come from this part (right above the wheel).

Step 6: See It Grows

You can stick as many as you want to.

Step 7: The Left Side Panel and the Light

Here you can see the light plug. to unplug it is easy if you have a small finger.

below and stuck to the metal, I found an unused plug, wondering what is that connect to in other versions. (mine is Argentina version, has not any active safety feature.

Step 8: What Is This!?

Curiosity: I found a meaningless plastic cover below the light! it may be useful in some of the full configured versions, I wonder if you find something interesting let me know, I will publish your photo here. thx.

pd: misteriy solved (thanks to jerrymildred from, it's to open the fuel tank cover from inside, when in case it stuck.

Step 9: Done Yet?

Well, after put them back together, I decided to let the central part untouched, it's very easy to add more foam but I want to save some panels, may this part using just a piece of ordinary carpet. depends on the real effect on the road.

I am sorry I can not tell the test run result as we are in quarantine for COVID-19. promise publish this final part soon.

By the way, I have a Fan Page for Prius 2018 in Argentina, also published this job, with details in spanish, for your reference if you speak Spanish:

If you will like to chat with more Prius users about this topic, you can also visit here, the Priuschat forum where I published this Project, and any feedback/opinions are avaliable!