Thank you for posting this article. I'm in charge of the electronics package of a Formula SAE team, and our wiring harnesses follow many of the practices found in this guide. I personally have been astounded by the fact that many of the assumptions we make with hobbyist-grade electronics go out the window when designing for motorsports. You can expect to find that at some point, water/fuel/oil/brake fluid will fall on your wiring. Seemingly sturdy connections will only misbehave under specific conditions such as high-speed cornering, making them difficult to debug.

Another thing I've also found shocking is how quickly the expenses can rack up. The Deutsch Autosport connectors listed in the article almost universally start at around $30-40 per connector. Heatshrink products are also very pricey, with the additional downside that if you make a mistake in the manufacturing process there is no way to re-use them once they've been cut off.