RubberDucky

I'm building a USB socket for my socketless car... My general concept is a standard car USB charger like this one: http://www.dealextreme.com/p/car-cigarette-powered-1000ma-usb-adapter-charger-black-dc-12v-40470 (it doesn't come with a fuse protection which i'll add...) and a 4 socket USB port i hacked from a computer motherboard. Do i need to make any changes to the charging adapter if i'm connecting 4 devices at once? let's assume i'm connecting 2 samsung galaxy SII and 2 5v 500mhh devices (GPS navigators). thanks.