if I bought a full setup from bestbuy which I did I think was 1 sub / 1 amp and they installed it was like 500$
but then I ended up selling them to a buddy ..

if I went back to best buy and got something new would they resintall it for free without reciept?
they could tell they installed it by the way they did it / what they used?
I left the cord still running thru my car and its just sitting in my trunk ready to be used but
they could attach the cords to the amp / sub for free you think or no?

No they are modular with their install cost so if its just an amp sub they charge for that by itself compared to a full install charge.

they even have rates for putting the subwoofer in the box so just be prepared to pay for those parts of the install because there is no reason they'd install anything for free.

well when I bought them they said since I paid for the installation they said I could get it for free with future purchases
or if something messed up with the subs

but I dont have the receipt thats why I was wondering but as long as they charge me for just the sub/amp not a full install
cause literally it would take less then 5 min to hook wires up Im just a dumbass and dont know how ha

yeah the wiring is easy and there are tons of youtube videos that show how.

short of not knowing what + and - mean for electrical wires you can't screw this up as long as you take the fuse out of the main power wire before doing it.

if you had your receipt and had more than someones word about the secondary install i'd say go for it but in this case you are better off just doing it at home.