My understanding is the Simpson brand hybrid system works with a traditional car retractable shoulder seatbelt (and 4/5/6 point). The Hans brand with the stiff design that extends down to your chest should be used with dual shoulder harnesses. Simpson and Hans are two brands sold under the same company.
The one thing I remembered strongly when trying on hans devices was feeling like $400 or whatever it is now for the plastic, really felt like the company was printing money for the materials involved.