public function save_vehicle_post_meta( $post_id, $post, $is_update ) {
			/**
			 * Do not continue if the post is being moved to the trash or if this is
			 * an auto-draft.
			 */
			if ( in_array( $post->post_status, array( 'trash', 'auto-draft' ), true ) ) {
				return;
			}

			// Abort if autosave or AJAX/quick edit.
			if ( ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE )
				|| ( defined( 'DOING_AJAX' ) && DOING_AJAX )
			) {
				return;
			}

			// is this a vehicle?
			if ( ! empty( $_POST['post_type'] ) && INVP::POST_TYPE !== $_POST['post_type'] ) {
				// no, don't create any meta data for vehicles.
				return;
			}

			/**
			 * Tick the last modified date of this vehicle since we're saving changes.
			 * It looks like this: Tue, 06 Sep 2016 09:26:12 -0400
			 */
			$offset           = sprintf( '%+03d00', intval( get_option( 'gmt_offset' ) ) );
			$timestamp_format = 'D, d M Y h:i:s';
			// use post_modified to set last_modified.
			$post_modified = DateTime::createFromFormat( 'Y-m-d H:i:s', $post->post_modified );
			$timestamp     = $post_modified->format( $timestamp_format ) . ' ' . $offset;
			$key           = apply_filters( 'invp_prefix_meta_key', 'last_modified' );
			delete_post_meta( $post_id, $key );
			update_post_meta( $post_id, $key, $timestamp );

			/**
			 * If this is not an update or there is no date entered post meta value,
			 * set the date_entered meta value using the post_date
			 */
			if ( ! $is_update || empty( INVP::get_meta( 'date_entered', $post_id ) ) ) {
				// use post_date to set date_entered.
				$post_date = DateTime::createFromFormat( 'Y-m-d H:i:s', $post->post_date );
				$timestamp = $post_date->format( $timestamp_format ) . ' ' . $offset;
				$key       = apply_filters( 'invp_prefix_meta_key', 'date_entered' );
				delete_post_meta( $post_id, $key );
				update_post_meta( $post_id, $key, $timestamp );
			}

			if ( empty( $_POST ) ) {
				return;
			}

			// Clear this value that is defined by a checkbox.
			update_post_meta( $post_id, apply_filters( 'invp_prefix_meta_key', 'featured' ), '0' );

			/**
			 * Loop over the post meta keys we manage and save their values
			 * if we find them coming over as part of the post to save.
			 */
			$keys   = INVP::keys();
			$keys[] = 'options_array';

			foreach ( $keys as $unprefixed_key ) {
				$key = apply_filters( 'invp_prefix_meta_key', $unprefixed_key );
				if ( isset( $_POST[ $key ] ) ) {
					if ( is_array( $_POST[ $key ] ) ) {
						// delete all meta, this is essentially for the options.
						delete_post_meta( $post->ID, $key );
						$options = array(); // collect the options to maintain a CSV field for backwards compatibility.

						foreach ( $this->sanitize_array( $_POST[ $key ] ) as $value ) {
							add_post_meta( $post->ID, $key, $value );
							if ( 'inventory_presser_options_array' === $key ) {
								$options[] = $value;
							}
						}
					} else {
						// String data.
						$value = wp_unslash( $_POST[ $key ] );
						// The values for keys with overlapping taxonomies might be slugs instead of term names.
						// inventory_presser_availability might arrive with a value of "for-sale" but we want to save "For Sale".
						$overlapping_keys = Inventory_Presser_Taxonomy_Overlapper::overlapping_meta_keys();
						if ( isset( $overlapping_keys[ $unprefixed_key ] ) ) {
							$term = get_term_by( 'slug', $value, $overlapping_keys[ $unprefixed_key ] );
							if ( false !== $term ) {
								$value = $term->name;
							}
						}
						update_post_meta( $post->ID, $key, sanitize_text_field( $value ) );
					}
				}
			}
		}