Molex MicroFit 3.0 are my gold standard for general purpose low voltage connectors. I buy from an electronics distributor (Digikey or Mouser) and crimp my own connectors. However, I did find a listing on Amazon for pre-crimped jumper wires and connector housings.
Does Sonic serve drinks in plastic cups now? It has been a while since I’ve been to any of them in WA.