I read about Model 3s losing their bumpers due to filling up with water. When I look underneath at the rear diffuser and I see that there are some small holes where it meets the undertray for drainage, so I decided to make some enlarged holes along the slope. Drilling holes in cars always reminds me of this clip from the Simpsons.
I decided to perform this modification without having to remove the diffuser from the rear bumper as that was way too much work. This is where my "speed" holes are position and they do not interfere with the rear deep trunk section.
|Location of each drain hole.|
|Starting left side hole using a 5/8" bit|
Made a parallel hole on the right side.
|Drain hole on right side.|
When I was installing new spring in the rear, I had to remove the rear diffuser, so I decided to study the pattern of the dirt that was collecting and staining the rear diffuser. The is the result of ~5000 miles of paved road driving.
|Dirt Collection from ~5000mi|
|Dirt concentration spots|
|Dirt collects on edges.|
|New smaller drain holes added to each edge|