20 conductor harness wires too short??

Question

I don't understand how people are installing these units, I can't find any way for the wiring to reach the passenger side kick panel.   The wires are at least 1 foot too short on the 20 pin connector so is there a trick to the install or do I need to buy an extension?  I was hoping to not splice in sections of wire but I will if I have too.
purchased the EVO-FORT1 standalone with THAR-FOR1

Wires that are too short are A17-19 on the 20 pin connector "A"

thanks