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Question

I'm looking for a solution to show related posts from a different CPT.
There are two CPT's (Projects and Products) both have multiple sub categories (don't know if that ok...).
When on a: Single Post > Projects CPT > SportsCars
in the footer it must show the latest two posts of: Products CPT > Sportscars
The code i have now just filters on the CPT, not the SubCategrories. This is the code of single_products.php:
<section class="content">
<div class="container">
<?php if (have_posts()) : while (have_posts()) : the_post(); ?>
<h1><?php the_title(); ?></h1>
<?php the_content(); ?>
<?php endwhile; endif; ?>
</div>
</section>
<div class="container">
<div class="divider-small"></div>
</div>
<section class="news">
<div class="container">
<h2>Related projects</h2>
<div class="row">
<?php
$wp_query = new WP_Query(array('post_type' => 'projects', 'post__not_in' => array( $post->ID ), 'showposts' => 2));
$i = 0;
if ( $wp_query->have_posts() ): while( $wp_query->have_posts() ) : $wp_query->the_post(); ?>
<div class="col-md-6 item">
<div class="<?php if($i++ == 1): echo 'green'; else: echo 'blue'; endif; ?> clearfix">
<div class="col-sm-6">
<div class="text">
<h3><?php the_title(); ?></h3>
<p><?php echo excerpt(20); ?></p>
</div> <!-- end text -->
<div class="meer-news">
Lees meer >
</div> <!-- end meer-news -->
</div> <!-- end col-sm-6 -->
<div class="col-sm-6">
<div class="image">
<?php
if ( has_post_thumbnail() ) :
the_post_thumbnail( 'news_latest' );
else:
// backup
endif;
?>
</div> <!-- end image -->
</div> <!-- end col-sm-6 -->
</div>
</div> <!-- end item -->
<?php endwhile; endif; wp_reset_query(); ?>
</div> <!-- end row -->
</div> <!-- end container -->
</section>