You want a 4S Li-po for an 1/18th scale car? Wow that'll be tuff to control. 3S in most cases it to fast. 2S packs is what people race with. Due to size constraints and it not really being something that a lot of people won't want it's not something you'll see any time to soon from us. If you want a custom pack made for a special project we can do that. But your limited to the size of the current cells we have. All special orders need to be called into the shop at 1-888-654-4450

Best regards,

Jason