So with most of the parts that I can get to now soundproofed, here is my summary.

 

My car is now exceedingly quiet, BMW 5 series quiet. It was quiet to start with being petrol with low db tyres, and it has been hard to quantify the gains given they have been done is stages over weeks, but the car is very quiet on all road surfaces.  I am very happy with the results.  I would strongly advise giving it a go if you plan to keep the car a while, you will gain valuable skills and end up with a more refined car.  The materials are also not expensive, I'd say I've spent around €200 total on silent coat and closed cell.

 

I've listed the jobs in the order I would suggest you do things.

 

Hood
Difficulty = Very easy
Risk of breaking clips, messing up =  None (cover engine bay with drop sheet in case you drop clips)
Downsides: Negligible gains
Should I do it?  Yes, valuable learning task.

 

Boot floor
Difficulty = Very easy
Risk of breaking clips, messing up =  None
Downsides: None, big gains to be got here, double up on the silent coat.
Should I do it?  Yes

 

Under rear seat
Difficulty = Easy (seat bench removal can be awkward)
Risk of breaking clips, messing up =  Medium
Downsides: You may need to replace the two slots where the seat plugs into (I didn't)
Should I do it?  Yes

 

Rear wheel arch
Difficulty = Easy
Risk of breaking clips, messing up =  None
Downsides: None, big gains to be got here, double up on the silent coat.
Should I do it?  Yes

 

Front wheel arch
Difficulty = Medium – Lots of screws, awkward to remove and refit.
Risk of breaking clips, messing up =  Low
Downsides: None, big gains to be got here, double up on the silent coat. Silent coat the plastic liner as well as metalwork.
Should I do it?  Yes

 

B Pillar trim
Difficulty = Medium – don’t lose t20 screw and refit carefully, wear latex gloves
Risk of breaking clips, messing up =  Medium/high, don't force anything refitting, if it requires force things are not lined up.
Downsides: None.
Should I do it?  Yes

 

Inside rear boot hatch
Difficulty = Medium – make sure to prise clips at the right points
Risk of breaking clips, messing up =  Low (assuming you don't remove liner fully, just enough to reach in)
Downsides: My hatch is now noticeably heavier to lift, don't overdo the silent coat.
Should I do it?  Maybe

 

Rear Door
Difficulty = Hard – awkward job if you don't remove the electrical connectors and door cable, limited surface area to cover
Risk of breaking clips, messing up =  Medium/high.  Have replacement clips to hand.
Downsides: Negligible gains, broken clips.
Should I do it?  I wouldn't bother

 

Top tips:
Always have all tools within easy reach.
Use magnetic Torx screwdrivers
Double up on the silent coat if space allows, one layer is a false economy.  Having gone to the trouble of gaining access be liberal.
With all the above, everything always went back together really well, all holes lined up, if they don't you have done something wrong so pause, never force anything.
Pace yourself, speed is the enemy of these jobs.

Enjoy!

 

 

 

 

Nice summary.

 

Original thread with guides

 

What tyres are you using?

Edited 21 May, 20197 yr by digifish

3 minutes ago, digifish said:

Nice summary.

 

What tyres are you using?

 

Debica Presto UHP 2 215/55 R17 - 67db

7 hours ago, Steviedakota said:

 

Debica Presto UHP 2 215/55 R17 - 67db

That is the lowest noise rating I have ever seen. Well done. 

as next i'll try find with acoustic foam inserts
 

Edited 22 May, 20197 yr by MartiniB

23 hours ago, Steviedakota said:

 

So with most of the parts that I can get to now soundproofed, here is my summary.

 

...

 

Under rear seat
Difficulty = Easy (seat bench removal can be awkward)
Risk of breaking clips, messing up =  Medium
Downsides: You may need to replace the two slots where the seat plugs into (I didn't)
Should I do it?  Yes

 

 

I just popped my rear bench front and had a look underneath. There seems to be some sort of material padding already covering the metal, was that the case with you?

 

 

Edited 22 May, 20197 yr by digifish

No, mine was bare metal. Do you have a photo?

Fantastic post 🙂 When you available to do mine ? 😉

12 hours ago, Steviedakota said:

No, mine was bare metal. Do you have a photo?

 

Little difficult to photograph ... in this pic I raised the front of the seat and photographed in the gap. The meterial is about 5 mm thick. The top is a smooth perforated material, underneath is 2-3 mm of flocking/foam

 

 

 

Edited 23 May, 20197 yr by digifish

4 hours ago, digifish said:

 

Little difficult to photograph ... in this pic I raised the front of the seat and photographed in the gap. The meterial is about 5 mm thick. The top is a smooth perforated material, underneath is 2-3 mm of flocking/foam

 

 

 

 

Interesting, mine (Dec 2015) didn't have that. What year is yours? Wonder if they added more soundproofing elsewhere too.

40 minutes ago, Steviedakota said:

 

Interesting, mine (Dec 2015) didn't have that. What year is yours? Wonder if they added more soundproofing elsewhere too.

 

November 2018 build. BTW I bought a set of new seat grommets. since removing my rear bench left it a little loose, still locked but now would pull up a few mm.  About $10 USD for 2. Part# 5G0 886 373

 

 

I will completely remove the rear seat when I get them and see what's what

Edited 23 May, 20197 yr by digifish

As promised, here is all you ever wanted to know about VAG - Seat grommets and why you (may) need to replace them. Part Number: 5G0886373

 

 

These cost about $5 USD each. After seeing the genuine item, if you can find a cheaper replacement from eBay/AliExpress etc, you should be fine. There are no real risks apart from the clip breaking which will only mean the front of the seat squab would move up and down a little. If you live close to an Audi, VW or Skoda dealer it will be similar cost to pick up some genuine clips compared to 3rd party alternatives (delivered).

Edited 24 May, 20197 yr by digifish

On 22/05/2019 at 19:19, MartiniB said:

as next i'll try find with acoustic foam inserts
 

 

That has got me thinking...

 

Do you think the acoustic foam inserts could be sourced / purchased and secured into a new set of tyres before putting them on the rims?

Here is some further info; https://www.tirerack.com/tires/tiretech/techpage.jsp?techid=336

1 hour ago, ope126 said:

 

That has got me thinking...

 

Do you think the acoustic foam inserts could be sourced / purchased and secured into a new set of tyres before putting them on the rims?

Here is some further info; https://www.tirerack.com/tires/tiretech/techpage.jsp?techid=336

 

I'd be very be very nervous about meddling with the tyre, there is a lot of heat, energy going on there. If they detached inside what then, balancing could go out the window at best. I think this is one area where a retrofit is not a good plan!

3 hours ago, ope126 said:

Do you think the acoustic foam inserts could be sourced / purchased and secured into a new set of tyres before putting them on the rims?

no 😞

-> https://www.briskoda.net/forums/topic/447954-tyreroad-noise-advice/?do=findComment&comment=5038848