TICONN 150 PCS Solder Seal Wire Connectors, Heat Shrink Butt Connectors, Waterproof and Insulated Electrical Wire Terminals, Butt Splice (150PCS)

https://a.co/d/0frimZ6E These connectors are easy to use and work great when used properly.Boss floating screen head units are not bad for the money and they have a good low level output and a decent built in amp. You need to make sure your cars CAN Bus can communicate with your head unit. PAC or Scosche make inexpensive ones.