The only downside to using one of these, is that your pulling the current of two or more devices through one DC power outlet circuit. Devices that have a battery, I.E., GPS, or cell phone, typically don't draw hardly any current, so it would take a whole bunch of devices to overload the circuit, which will result in blowing a fuse. UNDER NO CIRCUMSTANCES, UP THE RATING OF THE FACTORY FUSE. If you want to add more DC power outlets, it would be very easy, basically, you'll need an outlet, (can get them at auto parts store in the electrical section), wire, a fuse block/in-line fuse holder, and some terminals (ring style and maybe spade). Easiest way to hook it all up would be find a mounting spot for the outlet, run one wire towards a 12VDC power sourse (battery), just before the power source, hook up the fuse holder, then continue to the power source, on the outlet, hook up the wire you ran, to the center terminal of the outlet, (TYPICAL), now you need a ground, run a wire from the ground terminal of the outlet, usually the outer terminal, (TYPICAL), to a bare spot of metal on the vehicle, may have to drill a hole, but if you look hard enough, you should be able to find somewhere to connect the ground, once the ground is hooked up, and the power wire is connected to a power source, (battery), and a fuse is installed in the holder, the outlet will be ready to use. If its wired straight to the battery, it will be hot/live, all the time, so your device will function regardless of key position.
This was probably more info than you wanted, but I hope it helps. Youll probably be ok just using your splitter.
