[PhilJ]

I'd suggest you just include the manufacturer names in your product names.

Or, create a separate manufacturer dropdown, eg.

<form method="get" action="manufacturers.php">
<select name="mid" onchange="this.form.submit()">
 <option value="0" selected>{$lng.lbl_manufacturers}...</option>
 {section name=mid loop=$manufacturers_menu}
 <option value="{$manufacturers_menu[mid].manufacturerid}"{if $mid eq $manufacturers_menu[mid].manufacturerid} selected{/if}>{$manufacturers_menu[mid].manufacturer}</option>
 {/section}
</select>
</form>

v4.4.x

<form method="get" action="manufacturers.php">
<select name="manufacturerid" onchange="this.form.submit()">
 <option value="0" selected>{$lng.lbl_manufacturers}...</option>
 {section name=mid loop=$manufacturers_menu}
 <option value="{$manufacturers_menu[mid].manufacturerid}"{if $mid eq  $manufacturers_menu[mid].manufacturerid}  selected{/if}>{$manufacturers_menu[mid].manufacturer}</option>
 {/section}
</select>
</form>