Yuriy should use git and gist more often

alternate_control_syntax.md

Here's your code revised to use alternate syntax for control structures, convenient for using within templates:

<?php $cont_disp = ($cont_disp); ?>
<?php if ($cont_disp[0] == ""): ?>

    <!-- show nothing -->

<?php else: ?>

    <div id="car-Description" class="box-round">
        <div id="title-text-center">
            <h3>Vechicle Description</h3>
        </div>
        <?php $cont_disp = the_content(); ?>
    </div><!--End car-Description-->

<?php endif; ?>

hide_html_if.php

<?php 
$cont_disp = ($cont_disp);
if ($cont_disp[0]=="") { ?>
            <!-- show nothing -->
                <?php } else {?>
            <!--Description-->
            <div id="car-Description" class="box-round">
                <div id="title-text-center"><h3>Vechicle
Description</h3></div>
                
                <?php $cont_disp = the_content(); ?>
                    
</div><!--End car-Description-->
            <!--End Description-->
            
            <?php } ?>

with_clean_indentation.md

Here's your code revised, to have clean indentation and take advantage of some white space.

<?php

$cont_disp = ($cont_disp);

if ($cont_disp[0]=="") { ?>

    <!-- show nothing -->

<?php } else {?>

    <div id="car-Description" class="box-round">
        <div id="title-text-center">
            <h3>Vechicle Description</h3>
        </div>
        <?php $cont_disp = the_content(); ?>
    </div><!--End car-Description-->

<?php } ?>

Can you spot your problem now?

with_comments.md

Here's your code, with my comments pointing out questionable areas:

<?php $cont_disp = ($cont_disp); /* <-- this looks wierd . . . */ ?>
<?php if ($cont_disp[0] == ""):
/* What is the value of $cont_disp[0]? What were you expecting? */ ?>

    <!-- show nothing -->

<?php else: ?>

    <div id="car-Description" class="box-round">
        <div id="title-text-center">
            <h3>Vechicle Description</h3>
        </div>
        <?php $cont_disp = the_content();
        /* What does the_content() function return?
        Did you mean to `echo` something here? */ ?>
    </div><!--End car-Description-->

<?php endif; ?>