checking (if) and selecting children/parent in jquery

Question

My html:

<div class="red-box">
<h2>
<a href="#">My Cars</a>
</h2>

<div class="block_left layout2">
    <div class="part1">
        <div class="gallery_block">
            <div class="block_topic">1</div>
            <div class="block_topic">2</div>
            <div class="block_topic">3</div>
        </div>
    </div>
</div>

<div class="red-box">
<h2>
<a href="#">My Bikes</a>
</h2>

<div class="block_left layout2">
    <div class="part1">
        <div class="gallery_block">
            <div class="block_topic">1</div>
            <div class="block_topic">2</div>
            <div class="block_topic">3</div>
        </div>
    </div>
</div>

</div>....

There are a lot of "red-box" divs with different titles in <h2><a href="">TITLE</a></h2>like in example above. And I need to select and change only one - "red-box" -> "block_left" -> "part1" -> "gallery_block" -> "block_topic" which contains "3" and do it only in single "red-box" which got <h2><a href="">My Cars</a></h2>

So, I am doing following:

    if ($(".red-box").children("h2").children("a").children("span:contains('My Cars')").length > 0) 
    {
// it finds the "red-box" which i need but how to select
// <div class="block_topic">3</div> in the "red-box" whose href has "My Cars"?
}

Thanks

Answer 1

$('.red-box').has('h2:contains(My Cars)').find('div.block_topic').eq(2);

http://jsfiddle.net/L5YBf/1/