Is the manual newing-up of the ServiceProductDataProvider with RegisterInstance not the same as the Register .SingleInstance() ??
The RegisterInstance allows you to register a single instance in AutoFac.
The difference between RegisterInstance and RegisterType + SingleInstance methods is that the RegisterInstance method allows you to register an instance not built by Autofac.
But both solution will result in registering a singleton in Autofac.
By the way, both registration are equivalent in the following code sample
var instance = GetInstanceFromSomewhere();
builder.RegisterInstance<IService>(instance);
builder.Register(c => instance).As<IService>().SingleInstance();