There is no direct support for driver installation. So you have to inject it:
Though you may need some further XML adjustments. I am not good at DifxAppExtension at all.
project.WixExtensions.Add("WixDifxAppExtension.dll");
project.WixNamespaces.Add("xmlns:difx=\"http://schemas.microsoft.com/wix/DifxAppExtension\"");
project.Compiler.WixSourceGenerated += Compiler_WixSourceGenerated;
project.Compiler.PreserveTempFiles = true;
project.BuildMsi();
}
staticvoid Compiler_WixSourceGenerated(System.Xml.Linq.XDocument document)
{
XNamespace n = "http://schemas.microsoft.com/wix/DifxAppExtension";
document.Descendants("File")
.Single(e=>e.HasAttribute("Source", a=>a.EndsWith("MyDriver.sys")))
.Parent
.Add(new XElement(n + "Driver")
.AddAttributes("AddRemovePrograms=no; Legacy=no; PlugAndPlayPrompt=no; Sequence=1"));