diff --git a/lib/cartodb/carto_data.js b/lib/cartodb/carto_data.js
index fb4eb354..355c489a 100644
--- a/lib/cartodb/carto_data.js
+++ b/lib/cartodb/carto_data.js
@@ -90,7 +90,7 @@ module.exports = function() {
                     that.getId(req, function(err, user_id) {
                         if (err) throw new Error(err);
                         var dbuser = _.template(global.settings.postgres.db_user, {user_id: user_id});
-                        _.extend(req.params, {dbuser:dbuser});
+                        _.extend(req, {dbuser:dbuser});
                         callback(err, true); 
                     });
                 } else {
diff --git a/lib/cartodb/cartodb_windshaft.js b/lib/cartodb/cartodb_windshaft.js
index 134f6010..5f5919d8 100644
--- a/lib/cartodb/cartodb_windshaft.js
+++ b/lib/cartodb/cartodb_windshaft.js
@@ -27,45 +27,12 @@ var CartodbWindshaft = function(serverOptions) {
 
     serverOptions.beforeStateChange = function(req, callback) {
         var err = null;
-        if ( ! req.params.hasOwnProperty('dbuser') ) {
+        if ( ! req.hasOwnProperty('dbuser') ) {
           err = new Error("map state cannot be changed by unauthenticated request!");
         }
         callback(err, req);
     }
 
-    serverOptions.afterStyleChange = function(req, data, callback) {
-        if ( req.params.hasOwnProperty('dbuser') ) {
-          // also change the style of the anonim. request
-          var params = _.extend(req.params); // make a copy here
-          delete params.dbuser;
-          var style = req.body.style;
-          var that = this;
-          this.setStyle(params, style, function(err, data) {
-            if ( err ) callback(err, null);
-            else that.afterStateChange(req, data, callback);
-          });
-        } else {
-          callback(new Error("map style cannot be changed by unauthenticated request!"));
-        }
-    }
-
-    serverOptions.afterStyleDelete = function(req, data, callback) {
-        if ( req.params.hasOwnProperty('dbuser') ) {
-          // also change the style of the anonim. request
-          var params = _.extend(req.params); // make a copy here
-          delete params.dbuser;
-          var that = this;
-          this.delStyle(params, function(err, data) {
-            if ( err ) callback(err, null);
-            else that.afterStateChange(req, data, callback);
-          });
-        } else {
-          callback(new Error("map style cannot be deleted by unauthenticated request!"));
-        }
-    }
-
-
-
     // boot
     var ws = new Windshaft.Server(serverOptions);
 
diff --git a/lib/cartodb/server_options.js b/lib/cartodb/server_options.js
index 046aaa00..76447bc5 100644
--- a/lib/cartodb/server_options.js
+++ b/lib/cartodb/server_options.js
@@ -35,6 +35,14 @@ module.exports = function(){
         // for cartodb, ensure interactivity is cartodb_id or user specified
         req.params.interactivity = req.params.interactivity || 'cartodb_id';
 
+        req.params.processXML = function(req, xml, callback) {
+          if ( req.dbuser ) {
+            // Only edit XML when authenticated
+            xml = xml.replace(/(<Parameter name="user"><!\[CDATA\[)[^\]]*(]]><\/Parameter>)/, "$1" + req.dbuser + "$2");
+          }
+          callback(null, xml);
+        }
+
         Step(
             function getPrivacy(){
                 cartoData.authorize(req, this);
diff --git a/test/unit/cartodb/req2params.test.js b/test/unit/cartodb/req2params.test.js
index 0431a194..76348b6d 100644
--- a/test/unit/cartodb/req2params.test.js
+++ b/test/unit/cartodb/req2params.test.js
@@ -21,7 +21,7 @@ suite('req2params', function() {
           assert.ok(req.hasOwnProperty('params'), 'request has params');
           assert.ok(req.params.hasOwnProperty('interactivity'), 'request params have interactivity');
           assert.ok(_.isNull(req.params.dbname), 'could forge dbname');
-          assert.ok(!req.params.hasOwnProperty('dbuser'), 'could inject dbuser ('+req.params.dbuser+')');
+          assert.ok(!req.hasOwnProperty('dbuser'), 'could inject dbuser ('+req.params.dbuser+')');
           done();
       });
     });
@@ -53,11 +53,11 @@ suite('req2params', function() {
           // database_name for user "vizzuality" (see test/support/prepare_db.sh)
           assert.equal(req.params.dbname, 'cartodb_test_user_1_db');
           // id for user "vizzuality" (see test/support/prepare_db.sh)
-          assert.equal(req.params.dbuser, 'test_cartodb_user_1');
+          assert.equal(req.dbuser, 'test_cartodb_user_1');
  
           opts.req2params({headers: { host:'vizzuality' }, query: {map_key: '1235'} }, function(err, req) {
               // wrong key resets params to no user
-              assert.ok(!req.params.hasOwnProperty('dbuser'), 'could inject dbuser ('+req.params.dbuser+')');
+              assert.ok(!req.hasOwnProperty('dbuser'), 'could inject dbuser ('+req.params.dbuser+')');
               done();
           });
       });