jQuery Remote Validation gets unobtrusively driven additional parameters.

jquery.validate.unobtrusive-remote.js

(function($) {

    var originalRemote = $.validator.methods.remote;

    $.validator.methods.remote = function(value, element, param) {

        param.data = {};
        if (param.dataSelector) {
            var dataToSend = $(element)
                .closest(param.dataSelector)
                .find(":input")
                .serializeArray();

            $.each(dataToSend, function() {
                param.data[this.name] = this.value;
            });
        }

        return originalRemote.call(this, value, element, param);
    };
}(jQuery));