It appears you do not have some basic knowledge on soundproofing. Those who are into hifi especially room acoustics will know that egg trays are not meant for soundproofing. It is more to provide minimal absorption and diffusion, a very cheap solution for music listening in hifi applications where people do not have budget for costly room acoustic products. For soundproofing, you need absorption, the higher absorption the better. Hence foam which is good in absorption. The denser and thicker the better as it will be able to absorb more, being a more effective soundproofing material.

By the way, there isn't any need to find out whether there is a difference with or without cardboard, and the need to do a comparison. I can tell you right now that if it's cardboard, in a blind test you will likely not be able to tell the difference in sound when it rains. Maybe in the frequency of 10 times you will get it correct in 5 tries.

Meaning you are the expert? And you opinion and ears needs no scientific validation? Things have to be factual right?

https://www.usc.edu/CSSF/History/2012/Projects/J1301.pdf

Some research done... with this atleast we can say you are correct la...

BTW chart to show what is 13Db

http://www.gcaudio.com/resources/howtos/loudness.html

I'm surely wasting my time with you. Not that I am an expert and validation isn't required. You can do all the test if you want. But as I have said earlier, the things will turn out as it will be. The most you will get reduction of 1dB or maybe 2 dB via dB meter. You may measure the readings and get a measurement. The sound levels may or may not go down if the cardboard is ineffective in blocking or absorbing the sound. In other words, it may not even go down 1 dB, no difference at all. The tone of the sound of rain drops may change, but the intensity remains.

As I have reiterated, a test can be done. Even if the measurements, (objective) are proven to have some "minor" difference in sound levels, subjectively if you take the blind test you will fail the test if your ears cannot pick up the differences.

Get it?

Right Mr Expert!

Sometimes, some things don't need validation. It just takes some common sense and experience, with some knowledge in room acoustics. You can do test and measurements, nobody is stopping nobody. I am not stopping you. In fact I will be happy if someone does the blind test! BUT, it will be a futile test as I have mentioned, with the cardboard, one can already expect the results.

But I have to say, some people claim to have GOLDEN ears and can pick up the most minute differences. However, in a blind test, they often fail.

Please don't call me an expert. I just have some experience. I used to use an SPL meter to measure the sound levels from my hifi system years ago, not some dB app built in handphones but a proper SPL meter. I'm not that techy anymore these days as I'm getting old.

Insulating the roof with cardboards is quite common actually.
Cheap and effective.

https://www.facebook.com/shorty5.kelvin/pho...pe=3&permPage=1
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https://scontent-dfw1-1.xx.fbcdn.net/hphoto...970&oe=56F1ACC2
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What fighting here ?

Anyone is really owner of the car ?

I did extensive soundproofing to my car (Passat) before so I know.

I didn't exactly hold the 2 boards, but they sure look like card boards to me with the VW logos on them. I'm not surprised if that's really the case either.

What's important actually is the headliner itself, the headliner used in my car and other continentals are made of thick foam and cotton textile, so the sandwich board they use between the headliner and the metal roof can be just corrugated cardboard pieces or some sort of treated resin.

The other luxury cars like BMW (latest models) and Mercedes (W204, W212) also have like boards in their roofs just like VW. Lexus actually uses 3M thinsulate in their door panels, can also see thick sponge like foams stuffed in the B pillars as well.

Actually that's not true. Comparatively speaking - stock to stock on a rainy day - comparing a typical Japanese sedan vs the Passat. Most mainstream Japanese car roof are just bare metal with a thin piece of headliner, so the roof really does sound like those zinc roof houses... very noisy. The Passat had corrugated cardbox pieces in between and a thick headliner piece so noise was also naturally a lot less so...

And when you factor in the prices - if we assume RM100 is the cost of soundproofing per car vs RM10 for cardboard pieces, the savings is rather substantial when you look at the number of cards they produce every year.

I don't see the big deal here. It is obviously effective up to a certain degree or else they wouldn't have put it in.
These are big automotive companies, that would have SPL meter , specialized equipment to measure so if it wasn't effective, they wouldn't have put it in.

Does cbu passat also used same material as ckd passat?

Same. Even the German luxury 3 continentals also doing the same things for their rides.

If this the type of styrofoam we found on packing, it catch fire faster than dry paper, and release poison gas when burn. It very dangerous material to use inside car cabin.

Tan Chong the culprit cons by reduce the car quality in Malaysia.

Duno why still got ppl buy this stupid car. Its not even French. This Fluence is actually a Korean car. Lousy piece of crap

It is peculiar that this model from Renault although French, is not being sold in Europe but rather in some Latin American countries, Middle East, North Africa, Egypt, China, Mexico and lastly, Malaysia. In other words, it is not an international model despite the car coming from an established car manufacturer such as Renault. Perhaps it is a budget car aimed for specific (not-so-demanding) markets.

The car is very rare on our roads though I have seen one or two Fluence earlier this year. The back of the car looks out-of-proportion and weird. Coming out from Tan Chong, not sure if the car is further stripped down in some areas, as what that was shown here.