Morris Minor Owners Club

I have done a fair bit on both my moggies. I used soundproofing available on a roll from some motor shops. It did make some difference but neither job was particularly thorough. What I have learned is the most important areas to concentrate on are the most difficult to get at.
No1 area is the bulkhead, ie every part between the front edge of the floor to the bottom of the windscreen. I don't know how to be thorough here because its so complicated and would appear to involve a fair bit of dismantling. As Denzil is a daily driver It's not something I fancy doing You have the parcel shelf, heater, dash and gloveboxes to work behind.
The other area to cover is the rear of the car. Some exhausts can be really boomy and it pays to insulate behind and under the rear seat and on the inside of the boot lid.
Hope that helps.

I can say from experience that an underbonnet quilt(felt faced
with black vinyl ) looks good but doesn't do much to lessen the
noise. One of the best ways to quieten the standard engine
is to fit a duplex timing chain conversion. As Petee says,under
the rear seat needs well padding,and you can get an awful lot
of noise from ill fitting door seals(put a piece of paper between
the door and the frame and close the door) now try to move the
paper right round the door(from the inside) if it is not tight at
various places then bend the flange on to which the door seal
fits until it IS tight. The boot lid should have a coating of a
tar like substance as standard to stop drumming. The most
effective place to insulate is the bulkhead but, unfortunately,
it is also the most awkward to do properly unless the car
was designed for it from the start.