Product picture has wrong aspect ratio

[Maurice M]

My first question here so please be light on me - I'm just a simple car guy 8-)

Joomla 2.5 and Virtuemart 2.6.6:
I added some products to my site and don't know what else I did but now the product picture is distorted; has the wrong aspect ratio. The thumbnail is fine, clicking on it gives me a distorted picture and enlarging THAT gives me again a lerge picture with the correct aspect ratio. How can I change that? Thank you,
Maurice
www.grandtouringusa.com

[GJC Web Design]

got some dodgy css there

change to (over ride)

.product-image-area {
    width: 100%;
    float: left;
}

.product-image-slideshow .big-image img#big-product-image {
    max-width: 100%;
    width: 100%;
    height: auto;
}

[Maurice M]

Thank you for your reply and it seems you sent a picture where the image shows correctly. Now, I've been racking my brain to see where I need to change override AND change the CSS - all I can find is these files. Is your code in one of these? If so I wasn't able to find it. Like I said I'm not familiar with this and I guess it shows. Thank you,
Maurice

[Maurice M]

Follow up:

I noticed that rt_halcyon is my *master* template so I looked in there and found these files (pictured). Anything I need to do with those?