[twulff]

This is the way I have done it:

# changes to product.php
add this code somewhere before the smarty assigns will happen like line #112
#
# Get the real manufacturer
#
$thisManufactorer = $product_info["manufacturerid"];
$manufacturer = func_query("SELECT * FROM $sql_tbl[manufacturers] WHERE manufacturerid = $thisManufactorer");
$smarty->assign("manufacturer", $manufacturer[0]["manufacturer"]);

#changes to customer/main/product.tpl
# where to place the code is up to you
<tr><TD align="left" valign="top">
Producer:

</td>
<TD align="left" valign="top">
{$manufacturer}
<font size=1 face=Arial>(click to get all productions of this producer)</font>

</td>
</tr>

I hope this will help you a little bit