You can find them online and yes as mentioned a few posts above, they are quite expensive. Steve Meade is working with Tony from Rockford Fosgate on a new device that will tell you whether you are clipping your gains or not. Check out his YouTube channel for more information.
I wouldn't go back to this installer again if I were you nor would I recommend any of your friends to him either. Your power & ground wires must always be the same size.
Your power and ground wires should both be the same size to maintain a balance. The "big 3" upgrade allows more electrical current to flow which in return gives you more power to use.
It's just like the saying goes, you don't know what you have until you lose it and most teenagers don't truly understand the freedom we have in America compared to other countries unfortunately. May God bless the souls of those that fell in honor while protecting us.
I also got very scared haha. I actually thought the driver was injured until I saw him move the camera after the accident and if it is real then that must suck for the dude recording.
I doubt i'm going to do either of those on this particular car as it is just a daily driver that I plan to sell once I get a job and save up as it has too many things that need repair. I will do the "big 3" upgrade though and hopefully my voltage will improve a little from that. Thank you everyone for your inputs.