The recommended method of storing images in the database is to have your images located on your web-folder - say a path might be /var/www/my_site_folder/catalogue_images/.
You then store any uploaded automobile images in the catalogue folder and you store the web path in the database, so let say your domain is www.my_site.com then you would loop through or select a model of car (in the database) and grab its' image name and then using php append the path together.
$image_path = "./catalogue_images/$my_selected_image_name_from_the_db";
then where you need to display it:
$image = "<img src='$image_path' alt='$my_short_description_from_the_db' />
Hope this helps.