So Elon mentioned, that Model 3 will have 1,5km of wires running all around. Model S has 3km. Shall we discuss that? If this video really has the full main harness, then this is extremely good result already (compared to BMW-s). Most popular way to reduce harness length is to use modules everywhere. For example, head and taillights - rather than having all kinds of sectors have separate wires, just using positive, negative and data wire is enough per one light assembly. Same with electric seats. Common positive, common negative and one data to actuate all memory/heating/motorized/SRS functions. Other ideas: One cooling fan for AC/glycol loops, no redundancy (except software limp mode if failed). Tailgate specific module (camera, taillights, buttons, all have common power and one/two data channels.. HUD with minimal wiring directly from main computer.