Additional Sound Insulation?

Hi All

This may be a sign of old age (!) but Im wondering if anyone has installed any additional sound insulation in a Integra VTI-R?

And if so - what did you do (and who did it)

Im looking to reduce the amount of road noise coming into the cabin.

So far Ive added some sound absorbing foam to the underside of the bonnet and that seems to have reduced some of the engine noise when standing outside the car.....

Are there any areas which are known to "leak" noise?

regards

Zac