Do you know what kind of output/spec does the alternator generate?
Ground kits some what help, but I don't think it hurt to have one. You don't have to run 10 wires on the engine bay like a spider web. Just 2 or 3 will be enought (batter - to Frame by the battery, batter- to alternator mount bolt/screw, and battery-to tranny). Adding wires that way will NOT void the factory warrantee because you are just improving existing wires. I have it install on my Supra and Matrix.
The next one you have to look to before replacing the alternator is the battery. What is it capacity? The PC doesn't survive cranking in my Matrix with stock 300+ CCA battery. Once replace with an Optima Red Top battery (910CCA), the PC survive cranking as well as no dimming when the the window roll to the top/bottom when you still hold the switch.
Most/all newer car has a very cabable alternator.