another product i saw this weekend at the car show works really good for the license plate, it was the dynamat license plate kit, but more or less all it has is a piece of extreme for the back of your plate and then a dynamte frame for the plate, but it was only 15 bucks so it was worth it to stop the plate from vibrating and rattling.
HU: Pioneer Premier P-720
Front: JVC 2 way 6.5" component system
Rear: Kenwood KFC-1687
Subs: (2) 2002 Kicker 15" L7's
Amps: (2) Infinity Beta Digital 300's
(2) 1 farad Stinger Power Caps
(2) 1 farad Monster Cable Monster Caps