I've sound proofed underneath the seats and the prop tunnel. Not fool proof but takes the edge off. I didn't try and do the box itself, might worth ago, I'd think it would be better to have the box possibly mounted on a sound insulating material but you'd have to be careful not to cause any undue movement in the drive, you don't want a noisy wobbly one as well. I have posted this already as has Blake Marvin, who did a far neater job than mine
