OK, to help you guys understand what the grounds are for...
Your car has a battery with + and - terminals. The - (negative) terminal is connect to the chassis for a reason. That way only positive power cables need to be run to all the parts of the car. ie. all your lights are grounded to the chassis, there's a little ground box all your black wires from the lights go to, without the chassis grounded, NOTHING WILL WORK!
To try and gain performance through grounding you need to follow this:
1) make sure you have a good battery! (have it tested if you are not sure)
2) Check the actual connections at the battery, not just to the posts, but the wires at the battery connectors, these can corrode!
3) Check the battery ground. This should be 4gauge. It is overkill, but this wire will hold a lot of current, so there is no reason to skimp. Make sure the cable is attached at a clean, ie. no paint, or scraped surface on the chassis. The more surface area the better. Adding a second ground will not hurt, if you are unsure of the first, add one.
4) undo every engine ground you can find, one at a time and re-scrape the grounding point to make sure it has a good connection, then reconnect it.
5) if the wires on your grounds are dark, ie. not shiny like copper should be, either cut the wire back to a fresh portion, or REPLACE the cables.
6) Replace any sketchy cables with 8gauge cable, for the short runs these cables have, it is more than enough, trust me, for less than 2 ft, 8gauge is plenty. Arospeeds kit is way overkill and is just made to look nice. You can make your grounds look nice with cool looking cable and descent routing methods.
7) Add a ground or two. Just run 8gauge cable from the chassis to an extra spot or two on the engine or tranny. Using either an intake manifold bolt, or valve cover bolt, run a ground to the chassis, ie. the stut tower (don't forget to scrape the paint)
8) if your lights dim at idle, check the tension on the alternator belt, it will make sure the alternator is getting driven.
MAKE SURE YOUR CAR IS WELL GROUNDED
Jung