Cars nowadays have extensive built in diagnostics and dealer technicians can easily fix things. But that's because people won't accept glued-in parts.
Except - wasn't there a Porsche or a BMW that had a glued on inlet manifold, and when it heat cracks it can't be directly replaced because the head cannot be reglued? I believe there's an engineering company that modifies the head to take a metal manifold.
Perhaps gluing in is a sign that something is being sold to the kind of people who think "It's gone wrong, let's buy a new one."