Supplier quality control is the responsibility of the vehicle manufacturer, in this case Toyota. Each lot of product is tested and certified to be in compliance with the manufacturer's specifications. DANA process and Toyota QA failed in this case.
Recall: 150,000 Toyota Tacoma pickups for frame rust
"........While this is the Tacoma's first rust-related recall, it's a continuation of a much bigger problem that Toyota had already attempted to fix. In 2008, Toyota was forced to extend corrosion warranties and even repurchase Tacoma pickups from the 1995-2000 and 2001-2004 model years -- a span covering roughly 800,000 vehicles -- because entire frames were rotting out. ...........
........Even while most automakers have perfected rustproofing, Toyota and others still get it wrong. In 2010, Ford recalled about 475,000 Windstar minivans for rusting rear axles that reportedly were falling off the frames and entered a customer-service fiasco when owners demanded Ford buy back their vehicles (eventually, it did). In March, Chrysler recalled nearly 210,000 Jeep Liberty SUVs for suspension components that could rust and possibly break off.........."
Personally I think Toyotas are just boring. As Chris Snell pointed out:
"The Tundra wasn't doing it for me. It was just okay for family road trips but parking it around town is a nightmare and offroad, it was a TuRD. Most incapable 4WD system I've ever driven." And as pointed out in several vehicle shootouts, Toyota trucks have fallen way behind other manufacturers. There is a reason Toyota is one of the top manufacturers: Highly competitive prices ......... managed at the supplier level through high volume/low cost and with simple systems.