<rule name="Old Objects 2" stopProcessing="true">
  <match url="^transportbilar/(nya|begagnade|miljobilar)/(.*)$" ignoreCase="true"/>
  <action type="Rewrite" url="/transportbilar/{R:2}"/>
</rule>

url.Action("Slideshow", "Object", new { id = objectId });

transportbilar/handlare/{id}/{criteria}
transportbilar/handlare
transportbilar
transportbilar/sokresultat/{criteria}
transportbilar/{brand}/{id}/{criteria}
{controller}/{action}/{id}

<%= Request.Path %>
<%= Request.RawUrl %>
<%= Request.ServerVariables["HTTP_URL"] %>

routes.MapRoute(
    "OldObject2",
    "transportbilar/{mycondition}/{make}/{id}",
    new { controller = "Object", action = "Slideshow" },
    new
    {
        mycondition = "nya|begagnade|miljobila"
    }
);

routes.MapRoute(
    "NewRoute",
    "transportbilar/{make}/{id}",
    new { controller = "Home", action = "Test" }
);
routes.MapRoute(
    "OldRoute",
    "transportbilar/{mycondition}/{make}/{id}",
    new { controller = "Home", action = "Test" },
    new
    {
        mycondition = "nya|begagnade|miljobila"
    }
);

<p>@Html.ActionLink("link", "Test", new { make = "testmake4", id = 5})</p>

public static string UrlAction(string actionName) {
        return String.Format("/{0}", actionName);
    }

    public static string UrlAction(string actionName, string controllerName) {
        return String.Format("/{0}/{1}", controllerName, actionName);
    }

    public static string UrlAction(string actionName, string controllerName, RouteValueDictionary routeValues) {
        string url = String.Format("/{0}/{1}", controllerName, actionName);

        var parameters = routeValues.Select(s => string.Format("{0}={1}", s.Key, s.Value))
            .Aggregate((current, next) => string.Format("{0}&{1}", current, next));

        return url+"?"+parameters;
    }