That's usually part of the big three upgrade. You shouldn't expect any major gains but when you notice how weak the factory grounds are it certainly can't hurt. Tao Designs has a kit designed specifically for our cars.
My accompanying positive upgrade - alternator to battety:
In theory it can help. Google for big 3 and you'll get tons of hits.
The kit DOOM mentioned I saw when I was researching. Frankly I think it's a bit half assed of a kit using 4awg wire everywhere and adding way too many redundant / not useful grounds. His website is gone now so I don't know if its even available anymore, but it was inexpensive compared to the full custom upgrade I'm slowly getting installed.
Any additional ground added to the already-grounded OEM wiring is, by definition, redundant. That said, the kit shown above is more than sufficient to achieve the best possible grounding and would provide a (barely) measurable improivement. Typically replacing the OEM strap with a better connection, and adding one additional good connection to the chassis is more than sufficient. The addition stuff is truly redundant.