Last 10% takes 50% of the time

I by no means am excellent it takes a while to get much done the cars are home and garage built not professionally. I HATE everything wiring related so I always horse trade wiring work done for parts or labor and I wont build cars for others because I know they are not perfect. Derbying has taught me alot
And even guys that dont derby. I urge you to go buy even a rusty old car and dismantle it entirely and sell off the good scrap the bad and it will teach you so much about orientation of small details and you will also realize even the same make and model of car were never built fully thr same. And also you gwt a chuckle over the years of hackery you find in cheap repairs!