In my country, it rain almost every afternoon. So its a lot of difference on the roof soundproofing. Before I sound proof, the rain drop on the roof plattering is deafening, such that any expensive hi fi is also useless. Need to shut off the hi fi due to the noise from rain drops. And also every time you by pass a puddle of water, you can hear psssh..... After soundproof, no more sound when you pass by such water pools.

As for other huge difference, I have a lot of motorcycles in my country. So when they pass by, it will be "wankkkk........" exhaust sound. After soundproof, almost cannot hear them pass by.

But pls note, the weight of vehicle will increase. And if you are after performance, you should not do this modification. It makes your car much heavier and slower in pick up. But for me, no issue as I already stroked and bored the engine to 1680cc, threw in 11.1:1 high compression piston, shaved head 2mm off, ported and polished the head, high duration 275 intake and exos camshafts with lightweight cam pulleys, lightweight crankshaft pulley, change 2 inch straight through exos, bored throttle bodies, light weight flywheel and performance clutch kit, so increase in power easily removed the side effect (heavy weight) of soundproofing. For stock performance aveo, such soundproofing will slow down the car performance.