Now I have also done the sound isolation to my car.
It was done by a car stereo installer here in Finland.
He used about 4 packages of Vibroplast, about 2 square metres of 4 mm bitum isolation and about the same with 2 mm bitum, other than Vibroplast.
On the doors he used Noxydol on the thicker parts.
He said that the weight of the car increased with about 50 kilos.
He isolated all the doors, floor and the whole trunk.
I have to say that it didn't help almost nothing to the road noise
So is there anything else to do?
Only thing left to do is to change the tires?
Now I have Michelin Primacy, 225/45/17.
Can I change to 205/50(55)17 or should I change the wheels too and buy 16 inch wheels+tires instead?
What brand of tires could be the most silent ones and would still be good tires?
Or is there something wrong with the sound isolation of my car? Shouldn't the sound isolation made make some kind of difference in the road noise?