Hi Everyone. I wanted to check with regulars to get some takes on this.

I came across a mod for the Lexus IS 350 that some people have posted on forums and youtube vids involving cutting a hole in the airbox to increase the amount of air coming into the intake.
From what it looked like, it gave a noticeable performance/acceleration increase in the videos that I saw.

Obviously a high flow air filter or new air intake would be better in general, but i'm looking to minimize costs and see which cheap mods work the best.
I understand that air intakes are designed specific ways to maximize airflow, and that putting a hole in the airbox will suck in air from the engine bay which could be warmer than the air coming in the beginning of the intake.
I'm just looking for any input on anybody who has tried it or heard about it and what they found with it.

I wouldn't bother poking holes in the factory intake. I would instead get high flow drop ins.

Poking holes in the airbox would likely introduce more dirt. With aftermarket drop ins you want to keep the air coming in as clean as possible.

The factory setup was designed to manage intake noise and draw air from lower in the car. Heat rises to the top so cooler air comes in from lower in the engine bay. With holes in the airbox, as the engine bay gets warmer, warmer air would likely come into the intake. Warmer air is thinner and you want denser cooler air for more oxygen. Hotter air thins the oxygen mix into the air/fuel mixture as it travels to the throttle.

The restriction isn't at the airbox, it's at the throttle plate. Your engine can't ingest more air than is provided by the current intake.

Those videos are made by baboons who have no clue what they're doing.

Want more performance? Do all the recommended maintenance, clean your throttle body, replace your plugs, remove excess weight, find lighter wheels / tires, and install driver mods (HPDE track days are a great start).

Here ya go, on the original topic: https://www.nicoclub.com/archives/kn-vs-oem-filter.html