You are in the right track.

Should do this project in stages. 1 week driving with sound deadening, and so on.

 

wow brave man nice job

 

 

I installed Dynomat on my 2009 Corolla S Turbo on all 4 doors, trunk lid, entire trunk and on the hood under the hood blanket. It sure made a huge difference inside the car.

 

I installed Dynomat on my 2009 Corolla S Turbo on all 4 doors, trunk lid, entire trunk and on the hood under the hood blanket. It sure made a huge difference inside the car.

This is a good start, you'll notice a lot bigger improvement if you add another later to seal the large opening in the door, like this

just insides:

opening sealed:

 

I did both of my front doors completely and there was a minimal effect on NVH other than lessening the noise of cars when they are passing by.
Have you considered getting better tires?
My 2011 Corolla felt like a completely different car when I got a set of Kumho TA11 touring tires and I'm planning on doing the same to my 2019 Corolla HB soon. I'll keep you posted on what the difference is.

 

The idea is to prevent the metal from vibrating. You don't need to cover it all or cover spaces to get a nice solid door that sound doesn't transmit from the metal. Mine made a huge difference as I did the inside of the outer door skin and the inner door also. I've never cover the holes to allow the air to move so I'm not sure what difference that would do.

 

The biggest difference you'll notice by sealing the open holes is in the audio quality coming from the speakers, not so much in sound deadening. It essentially turns the entire door cavity into a sealed speaker box, allowing the sound (energy) from your speakers to be used more efficiently. I've still only done the one door pictured above and the bass hits MUCH harder from that door than the others, because of the way I sealed the door.

 

How much does the sound deadening material costs for 4 doors?

 

Got new tires (Kumho Solus TA11) for my 19 Corolla HB SE today. They're a huge difference from the OEM Dunlop Enasave. Much less road noise and bumps are nicely damped. A much bigger difference than the sound deadening IMO.

 

Just think what it would be like with both! The sound deadening will not get worse like the tires as they wear.