diff --git a/src/app/code/community/FireGento/GermanSetup/Model/Tax/Config.php b/src/app/code/community/FireGento/GermanSetup/Model/Tax/Config.php
new file mode 100644
index 0000000..a5e01fd
--- /dev/null
+++ b/src/app/code/community/FireGento/GermanSetup/Model/Tax/Config.php
@@ -0,0 +1,88 @@
+<?php
+/**
+ * This file is part of the FIREGENTO project.
+ *
+ * FireGento_GermanSetup is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version 3 as
+ * published by the Free Software Foundation.
+ *
+ * This script is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+ *
+ * PHP version 5
+ *
+ * @category  FireGento
+ * @package   FireGento_GermanSetup
+ * @author    FireGento Team <team@firegento.com>
+ * @copyright 2011 FireGento Team (http://www.firegento.de). All rights served.
+ * @license   http://opensource.org/licenses/gpl-3.0 GNU General Public License, version 3 (GPLv3)
+ * @version   $Id:$
+ * @since     0.1.0
+ */
+/**
+ * Tax config model with new shipping tax class calculation
+ *
+ * @category  FireGento
+ * @package   FireGento_GermanSetup
+ * @author    FireGento Team <team@firegento.com>
+ * @copyright 2011 FireGento Team (http://www.firegento.de). All rights served.
+ * @license   http://opensource.org/licenses/gpl-3.0 GNU General Public License, version 3 (GPLv3)
+ * @version   $Id:$
+ * @since     0.6.2
+ */
+class FireGento_GermanSetup_Model_Tax_Config extends Mage_Tax_Model_Config
+{
+    const XML_PATH_SHIPPING_TAX_ON_PRODUCT_TAX = 'tax/classes/shipping_tax_on_product_tax';
+
+    /**
+     * Get tax class id specified for shipping tax estimation
+     *
+     * CUSTOM: Select shipping tax class based on highest product tax rate
+     *
+     * @param   store $store
+     * @return  int
+     */
+    public function getShippingTaxClass($store=null)
+    {
+        /* @var $session Mage_Checkout_Model_Session */
+        $session = Mage::getSingleton('checkout/session');
+
+        $quoteItems = $session->getQuote()->getAllItems();
+        $taxClassIds = array();
+        $highestTaxRate = null;
+
+        // Check if feature is enabled and if there are products in cart
+        if (!Mage::getStoreConfigFlag(self::XML_PATH_SHIPPING_TAX_ON_PRODUCT_TAX, $store)
+            || count($quoteItems) == 0
+        ) {
+            $taxClassId = (int) Mage::getStoreConfig(self::CONFIG_XML_PATH_SHIPPING_TAX_CLASS, $store);
+            return $taxClassId;
+        }
+
+
+        foreach ($quoteItems as $item) {
+            if ($item->getParentItem()) {
+                continue;
+            }
+
+            $taxPercent = $item->getTaxPercent();
+            if (is_float($taxPercent) && !in_array($taxPercent, $taxClassIds)) {
+                $taxClassIds[$taxPercent] = $item->getTaxClassId();
+            }
+        }
+
+        ksort($taxClassIds);
+        if (count($taxClassIds)) {
+            $highestTaxRate = array_pop($taxClassIds);
+        }
+
+        if (!$highestTaxRate || is_null($highestTaxRate)) {
+            $taxClassId = 0;
+        } else {
+            $taxClassId = $highestTaxRate;
+        }
+
+        return (int) $taxClassId;
+    }
+}
\ No newline at end of file
diff --git a/src/app/code/community/FireGento/GermanSetup/etc/config.xml b/src/app/code/community/FireGento/GermanSetup/etc/config.xml
index 613684e..2bcfecd 100644
--- a/src/app/code/community/FireGento/GermanSetup/etc/config.xml
+++ b/src/app/code/community/FireGento/GermanSetup/etc/config.xml
@@ -6,11 +6,6 @@
         </FireGento_GermanSetup>
     </modules>
     <global>
-        <models>
-            <germansetup>
-                <class>FireGento_GermanSetup_Model</class>
-            </germansetup>
-        </models>
         <blocks>
             <germansetup>
                 <class>FireGento_GermanSetup_Block</class>
@@ -26,6 +21,16 @@
                 <class>FireGento_GermanSetup_Helper</class>
             </germansetup>
         </helpers>
+        <models>
+            <germansetup>
+                <class>FireGento_GermanSetup_Model</class>
+            </germansetup>
+			<tax>
+				<rewrite>
+					<config>FireGento_GermanSetup_Model_Tax_Config</config>
+				</rewrite>
+			</tax>
+        </models>
         <resources>
             <germansetup_setup>
                 <setup>
diff --git a/src/app/code/community/FireGento/GermanSetup/etc/system.xml b/src/app/code/community/FireGento/GermanSetup/etc/system.xml
index 8670918..b9a3096 100644
--- a/src/app/code/community/FireGento/GermanSetup/etc/system.xml
+++ b/src/app/code/community/FireGento/GermanSetup/etc/system.xml
@@ -253,5 +253,23 @@
                 </analytics>
             </groups>
         </google>
+        <tax>
+        	<groups>
+        		<classes>
+        			<fields>
+                        <shipping_tax_on_product_tax translate="label,comment" module="germansetup">
+                            <label>Shipping Tax Class on Product Tax Class</label>
+                            <comment>Set to "yes" if you want to calculate the shipping tax rate based on the highest product tax rate. Attention: This setting overwrites the tax class setting above!</comment>
+                            <frontend_type>select</frontend_type>
+                            <source_model>adminhtml/system_config_source_yesno</source_model>
+                            <sort_order>11</sort_order>
+                            <show_in_default>1</show_in_default>
+                            <show_in_website>1</show_in_website>
+                            <show_in_store>0</show_in_store>
+                        </shipping_tax_on_product_tax>
+        			</fields>
+        		</classes>
+        	</groups>
+        </tax>
     </sections>
 </config>
\ No newline at end of file