I have just fitted 2x12" vibe subs in the boot, but the boot now rattles like anything.
What is it thats rattling and how can I stop the rattling?

 

Its a common problem when subs are fitted

The bass causes lots of vibrations

Everything rattles from the spoiler to the lock mechanism to the boot trim etc

Only way to stop it is to dynamat everything

 

What do you use for the boot lock mechanism? Is it possible to wrap something round it to prevent that vibrating?

 

Try padding it with foam or sponge around where you can on it , just make sure not to foul up any moving parts

Make sure you check your jack etc as well and also your number plate

The number plate can often be quite noisy too