OBD II has spoiled us. When we were kids, we had to find misfires BY OURSELVES! Now drivers have a blinking Malfunction Indicator Lamp and diagnostic trouble codes telling us which cylinder is in trouble. You would think that would make our job easier, but we still need to find the cause.
The structural strength of the front and roofline of the passenger compartment depends heavily on the windshield and its bond with the A-Pillars, roof, and base where it connects to the upper frame rails. Replacement parts, installation materials, and procedures must meet safety standards.
What you use in your day-to-day career, no matter how high-quality, is necessarily different from what you need for high-performance work, in this case engine building.