After some frustrating moments of screws popping out, not being wide enough and generally some really annoying DIY moments I've got the sub firmly secured in my car, without the aid of bungee cord...

Now, as long as the boot floor carpet remains steady, so does the sub. Next job, as you can tell, is to hoover out the boot.

Did you nail it down??

At least its secure, have you thought about a simple false floor made up of MDF?

Looks alot tidier and you can mount the amp aswell.

My old Astra which I did myself, nowt too fancy but it was secure and looked tidy.

Only cost a bit for the MDF and the carpet. Not the best pic but the box and amp are recessed into the floor to locate them and all the wiring secured underneath. MDF lifts up to access the spare.

The supports are simply screwed down through the carpet, thru the thin timber below that, and with thin extra timber supports for the screws get extra grip... I could probably pull every single bit of timber there out with my bare hands and some serious force, but it does the simple job it needs to for me! :speaker:

I agree with Ross. False floor is needed.

Here's a picture of my clio boot build