Fatal Error on Mobile Car Details Page

I am getting this error when I click on a specific car from a search:

Fatal error: Cannot redeclare car_demon_display_similar_cars() (previously declared in /webroot/l/o/local015/demo2.carsalesspecialist.com/www/wp-content/plugins/car-demon/includes/car-demon-template.php:284) in /webroot/l/o/local015/demo2.carsalesspecialist.com/www/wp-content/themes/car-demon-mobile/single-cars_for_sale.php on line 434"

I could not even find the car-demon-template.php.  And line 434 of the single-cars_for_sale.php is the closing bracket for this function:

"function car_demon_display_similar_cars($body_style, $current_id) {
	global $wpdb;
	$car_demon_mobile_themepath = str_replace(str_replace('\\', '/', ABSPATH), get_option('siteurl').'/', str_replace('\\', '/', dirname(__FILE__))).'/';
	$car_demon_mobile_themepath = str_replace('widgets','',$car_demon_mobile_themepath);
	$car_demon_themepath = str_replace('car-demon-mobile', 'car-demon-theme', $car_demon_mobile_themepath);
	$my_tag_id = get_term_by('slug', $body_style, 'vehicle_body_style');
	$my_search .= " AND $wpdb->term_taxonomy.taxonomy = 'vehicle_body_style' AND $wpdb->term_taxonomy.term_id IN(".$my_tag_id->term_id.")";
	$str_sql = "SELECT wposts.ID
		FROM $wpdb->posts wposts
			LEFT JOIN $wpdb->postmeta wpostmeta ON wposts.ID = wpostmeta.post_id
			LEFT JOIN $wpdb->term_relationships ON (wposts.ID = $wpdb->term_relationships.object_id)
			LEFT JOIN $wpdb->term_taxonomy ON ($wpdb->term_relationships.term_taxonomy_id = $wpdb->term_taxonomy.term_taxonomy_id)
		WHERE wposts.post_type='cars_for_sale'
			AND wpostmeta.meta_key = 'sold'
			AND wpostmeta.meta_value = 'no'".$my_search.'
			ORDER BY ID LIMIT 4';
	$the_lists = $wpdb->get_results($str_sql);
	$car = '';
	$cnt = 0;
	if (!empty($the_lists)) {
		$car .= '<h3>'.__('Other Great Deals').'</h3>';
		$car .= '<div style="width:650px;height:225px;margin-top:10px;">';
		foreach ($the_lists as $the_list) {
			$post_id = $the_list->ID;
			if ($post_id != $current_id) {
				$cnt = $cnt + 1;
				if ($cnt < 4) {
					$show_it = 1;
					$stock_value = get_post_meta($post_id, "_stock_value", true);
					$vehicle_year = strip_tags(get_the_term_list( $post_id, 'vehicle_year', '','', '', '' ));
					$vehicle_make = strip_tags(get_the_term_list( $post_id, 'vehicle_make', '','', '', '' ));
					$vehicle_model = strip_tags(get_the_term_list( $post_id, 'vehicle_model', '','', '', '' ));
					$vehicle_condition = strip_tags(get_the_term_list( $post_id, 'vehicle_condition', '','', '', '' ));
					$title = $vehicle_year . ' ' . $vehicle_make . ' '. $vehicle_model;
					$title = substr($title, 0, 24);
					$mileage_value = get_post_meta($post_id, "_mileage_value", true);
					$detail_output = '<span class="random_title">'.$title.'</span>';
					$detail_output .= '<span class="random_text">';
						$detail_output .= 'Condition: '.$vehicle_condition.'';
					$detail_output .= '</span>';
					$detail_output .= '<span class="random_text">';
						$detail_output .= 'Mileage: '.$mileage_value.'';
					$detail_output .= '</span>';
					$detail_output .= '<span class="random_text">';
						$detail_output .= 'Stock#: '.$stock_value;
					$detail_output .= '</span>';
					$link = get_permalink($post_id);
					$img_output = "<img onclick='window.location=\"".$link."\";' title='Click for price on this ".$title."' onerror='ImgError(this, \"no_photo.gif\");' class='random_widget_image' width='180px' height='135px' src='";
					$img_output .= wp_get_attachment_thumb_url( get_post_thumbnail_id( $post_id ) );
					$img_output .= "' />";
					$ribbon = 'ribbon-just-added';
					$ribbon = 'ribbon-great-deal';
					if ($vehicle_condition == 'New') {
						$ribbon = 'ribbon-new';
					}
					else {
						if ($mileage_value < 60000) { $ribbon = 'ribbon-low-miles';	}
						$tmp_price = get_post_meta($post_id, "_price_value", true);
						if ($tmp_price < 12000) { $ribbon = 'ribbon-low-price';	}
					}
					$car .= '
						<div class="random_mobile" style="float:left;width:105px;height:185px;">
							<div class="random_img">
								<img onclick="window.location=\''.$link.'\';" style="margin-left:15px;" src="'. $car_demon_themepath .'images/'.$ribbon.'.png" width="146" height="146" alt="New Ribbon" id="ribbon">
								'.$img_output.'
							</div>
							<div class="random_description">
								'.$detail_output.'
							</div>
						</div>';
				}
			}
		}
		$car .= '</div>';
	}
	if ($show_it != 1) {
		$car = '';
	}
	return $car;
}

[Please use backticks, NOT quotation marks, for posting code]

Does anyone see where the error might be. I am not much of a coder myself so I cannot tell.

Tnx,
Lydia

https://www.ads-software.com/plugins/car-demon/