Nothing special, but nice

Alpine head, and front splits, Kicker subbie, cadence amp.
The problem:
Love the system, but now I get a lot of rattling noises XD, tis not a lot of bass, but enuff to get the chasis vibrating.
Cant hear it on the inside, but my mates telling me that it makes a bit of rattle on the outside

Anything I can do to reduce this? I know theres sound deadener, but any other alternatives?
Was thinking of getting some rubber stuff from clark rubber and sticking it on the panels or sumthing - cheap lol