Fit the harmonic damper to the rear subframe....
https://www.golfmk7.com/forums/index.php?threads/how-to-retro-fit-the-rear-subframe-harmonic-damper-from-the-audi-a3-saloon-2013.369369/
Wow, I didn’t know that even existed!
That’s the beauty of car forums.
A very interesting read.
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It’s funny, most requests on performance car forums are along the lines of “how can I get more exhaust/induction noise from my GTI/R as it’s too quiet...?”
The GTI is probably one of the quietest hot hatches, especially once the OE Bridgestones have been junked.
A Passat is really far more of a comparison to a 3 series.
The 3er is far more of a motorway cruiser, will probably have more sound insulation and BMW fit and finish generally seems to be a little better than VW’s.
In fact I didn’t realise how much scuttle flex a GTI had until after I’d spent the best part of an hour driving a new M135i over roads I commute on every day of the week.
The mk7(.5) has thinner metal panels than the mk6,5,4 etc which probably contributes to noise transmission into the cabin. No doubt recent cost cutting has included sound deadening too.
I can remember back in the mk1 and mk2 Golf days you could buy kits that were pre-cut to install under the bonnet, on the bulkhead and also under the carpeted areas plus even on the inside of the door panels.
Michelins are reasonably quiet, I’ll assume the car is otherwise standard?
My dad once had a sexy red Cortina GT that began making horrible noises from the engine, his solution was the age old remedy of “turn the radio up and it goes away”