True, it just takes patience. Also, I did mine without any soldering(other than extending the feed lines to the fuse box), I simply bundled and tucked excess wiring, less chance of electrical issues than from spliced wiring, even soldered joints sometimes crack. I'm not sure it's 100% relevant with the dsm ecu, but on some of the industrial equipment I worked on, the wiring length was taken into consideration on the signal from certain sensors, so changing lengths effected the signal of some circuits by changing the resistance.