Modern vehicles grow more complex and more computerized with every passing model year, and that complexity is starting to show up in the form of increasing dependability issues, even at Toyota, long the industry benchmark for durability. Recent recall actions tied to the automaker’s new twin-turbocharged 3.4-liter V6, which serves as a V8 replacement across high-volume body-on-frame models, including the latest Lexus GX, have only sharpened the concern.