I have a co-worker who ordered a bunch of heat resistant insulation from mcmaster carr, his 05 corollas odo stopped at 400,000/- the guy simply added this insulation to the firewall and engine room area - even on the hood, it looks like a generator engine room now - all shiny etc.

the other bit that makes the corolla super noisy is the wheel wells - all 4 of them are in the cabin, insulate them with heavy suppressor.

The doors also resonate at high speed, you would need to check the vapor barriers and even apply some thin foam on it too.

btw - the engine mounts also cause a lot of noise to be transmitted to the cab. along with the front subframe mountings.

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)