Well eventually got around to doing this today and £5 later im very pleased. Went to homebase and bought some recylcled plastic insulation and filled the rear quarters and its really made a difference to the sound of the rear speakers and also the car is much quieter
Give it a try for a £5 its a great mod for those with big wheels or low springs
Lift the rear seat bech forward and remove it.
Remove the the thumb screw behind the rear back rest.
Give the rear quarter a firm tug and it will come free, with a little jiggery pokery it will be easily removed within 5 mins
Fill the rear quarter as much as possible with the fibe insuation and put the panel back on


Hey presto, done, fin