Just wonder the replied so far can simply give you solution without asking for more details.

Before u jump into it, you need to clarify the area/problem you want to improve:
Simply said, what causing you want to sound proofing your Wira?

1. Tyre noise (Front or back?)?
2. Road roar?
3. Engine noise?
4. Wind noise?
5. Traffic noise?

There are sound absorbing, sound deadening and sound reflection. Each areas need different treatment combination.

The popular brand with high C/P ratio is STP currently, but seriously 500-600 won't get you a satisfaction result if you know what is 'sound proof'.

I owned a Saga BLM for 5.5 years now, started DIY soundproof since half year i owned it. Started from simple 4 doors soundproof using insufflex until now almost whole car soundproof (whole floor, inner wheel arc multiple layers, outer wheel arc, engine hood, outer firewall, fender, all doors except roof) using STP silver + Splen + BTP + Hood Solution. My knowledge is through my own research and many trial and error. Sometimes u think you are soundproof to solve sound A, but end up you mute the sound B but not A. Different car need different treatment, either you go find someone who really have good experience with Wira soundproof or u learn and DIY yourself. I give up on the former solution, because no one understand more on your car except your own. Sometimes you might impressed by those online photo where u saw the workshop soundproof for those Merz, BMW and alot of expensive continental, but they might not be able to soundproof your Wira to the level that u expect.

Soundproof is a tedious thing, when u soundproof door, traffic noise and some wind noise will reduce, but then u will start to hear a loud engine noise from dashboard and road roar from floor. Then u will continue with the floor soundproof, after that u will hear the noise coming again from door and firewall. Soundproof is never ending job, human ears will get used to it and after that the effect will be diminished.

So don't ask me where should you start to soundproof without any specific expectation. Your 500-600 budget won't get you an 'overall' improvement, u will get part of it but will loss the effect quickly once your ear get used to it. If you want overall, prepare some big cash and few working days or maybe weeks to do the whole car. A floor will need you at least 2-3 whole days if u DIY.

This post has been edited by coolkwc: Mar 27 2015, 10:04 PM

Actually most of the low end car suffer road roar problem. From what u said, road roar is a low frequency vibration noise caused by contact of tyre with the road, that noise frequency range is around 100-300Hz. Based on my own experience and judgement, this noise is caused by few factors. 1st, a hard tyre. Change to soft tyre u will immediately feel ur car is more airy, but tyre won't last long, after 10k the tyre become harden and the noise will come back again. The main contributor of this noise is due to bad suspension design. The suspension is not isolated well from the chassis and just can't absorb those tiny bump of the rough road, causing the vibration of the tyre transmit through the strut to chassis, and then causing ur whole chassis (floor, roof, door panel) to vibrate and resonant at the same frequency. This noise is annoying, it will kill ur ICE midbass sound, and kill ur ear in long run (highway drive). Basically u can't solve this problem by changing suspension, and will become worsen when u change ur rim to larger size(hence thinner side wall) and spring/absorber to sport type. The only way u can do is using mass to dampen the chassis vibration, where u can apply thick dampening sheet like STP gold to the whole floor panel. However the main problem of that is ur Axia adi a underpower car, adding mass will make it more worse in terms of power and fuel consumption.