Shielded or twisted pair

I am making a harness for a ford focus st and I’m keeping the stock components and pcm (powertrain control module). I want to just make a harness that routes everything inside the car to clear space in the engine bay. With that being said almost all the things that I’ve bin told need to be shielded are a twisted pair not shielded. When making this knee harness to minimize cost would it be okay if I stick with the twisted pairs? My assumption is yes I just would like a professionals opinion!