mspecDoesntWork.cs

namespace When
{
    [Subject(typeof())]
    public class Figuring_out_mSpec
    {
        It should_be_unspeced_here;
        It should_fail_here_too = () => 
            returnFalse().ShouldBeFalse(); // ShouldBeFalse is an extension method in mspec.
        It should_pass_here = () => 
            s.Contains("o").ShouldBeTrue(); // ShouldBeTrue is an extension method in mspec.
      
        static string s = "John";
        static void noop() {}
        static bool returnFalse(){return false;}
    }
}

The problem was you were assuming that http://jagregory.com/writings/behaviours-in-mspec/ shouldBetrue was part of the IVehicle contract.

The delegate It is just a void returning function (or procedure as they used to say in my day).