The fortwo has some really good sound proofing on the carpets but when it comes to the doors, boot and other panels it is non existent.

Aftermarket sound proofing is available from companies like dynamat and fatmat. It's pricey stuff but what a difference it makes in drowning out the noises from other cars or keeping the sound from our speakers in.

First things first, remove the panel or piece of trim you wish to apply the proofing to, clean the surface with a good de-greaser, cut the proofing to size and apply it with a roller.

The draw back in sound proofing is that its very heavy, so if you want a high speed dragster then this isn't the mod for you.

(Pictured below are the doors with fatmat applied to them.)