Hi Mick...
thick brush with Septone Sound Deadening Bitumen, i did the following...
the inner skin of the both doors (mine is a 3 door hatch...)
the inner skin of the quarter panels...
overall I did about 0.2mm thickness over a period of time...
i will invest in 4 steel stands and clean up the underside and sound deaden there too, and also go crazy on the wheel well... (ofcoz will do this over a hot summer...)