You will need to make adjustments to the product controller or product.php.
It might be worth making a copy of the product.php file from the Swipestripe folder and placing it into your "/mysite/code" folder
Product.php
Place the following under your Many_Many array
'RelatedProducts' => 'Product'
Then place the following under the controller
//Related Products
$gridFieldComplex = GridFieldConfig::create()->addComponents(
new GridFieldToolbarHeader(),
new GridFieldSortableHeader(),
new GridFieldDataColumns(),
new GridFieldManyRelationHandler(),
new GridFieldPaginator(10),
new GridFieldEditButton(),
new GridFieldDeleteAction(),
new GridFieldDetailForm()
);
$tablefield = new GridField(
'RelatedProducts',
'Related Products:',
$this->RelatedProducts(),
$gridFieldComplex
);
$fields->addFieldToTab('Root.RelatedProducts', $tablefield);
function RelatedProductsLimit($limit = '') {
return $this->owner->RelatedProducts("ProductID = " . $this->owner->ID, "", NUll, $limit);
}
Then inside your Product.ss file (Remember to also take a copy of this file and place it into your "/themes/*YOUR THEME*/template/layout" folder.
<% if RelatedProducts %>
<div id="relatedProductsWrap">
<div id="relatedTitle">
Related Products
</div>
<div id="related">
<% loop RelatedProductsLimit(4) %>
<a href="$Link" alt="Find out more about $Title" title="Find out more about $Title" class="eachRelated" <% if Last %>style="margin-right:0px;"<% end_if %> >
<% loop Images.First %>
$Image.SetRatioSize(160,180)
<% end_loop %>
<h4>$MenuTitle</h4>
$Amount.Nice
</a>
<% end_loop %>
<div class="clear"></div>
</div>
</div>
<% end_if %>
If my code copy is correct, you should have Releated Products as a tab on each of your products.
Then a grid field where you can select the related products you want.
They should all then show up as related products in your template.
Of course you will need to add some css to tidy the thing up.