Led fog lights that are plug and play will do absolutely nothing as far as lighting up the road goes. They are great for drls, but without a specifically designed housing, they won't do any good on the road.
By led tail lights I'm guessing you have the led bulbs? I would be careful with the cree's in those. If they do not come with an actual metal heatsink (my cree led reverse lights have a plastic one) then they will probably overheat and die after a relatively short period of time. Backup lights don't really need the proper heatsink because they aren't on for very long periods of time, but the tail lights are. The same goes for the front turn signals.
2007 Cobalt Ls Manual Coupe
Kenwood Excelon X996, RF T3 Components, RF Power 6x9s, Sundown Audio SA10, RF Power T600.4, Alpine MRP-1000, Kinetic HC-1800, Black headlights, FX-R HID 55W, Custom led tail lights, Led reverse lights, Airbox mod.