I've bin told that if I put a thick plastic plate under me cubby box unstead of the ally plate then it will be an mot fail, also that anything other than metal for filling the floor in is also an mot fail.
Pity that because the half inch plastic sandwich plate is warmer than the ally and would help keep the sound out.
Pity that because the half inch plastic sandwich plate is warmer than the ally and would help keep the sound out.