Hello,
I have seen provided sample and wanted to confirm you that I will make Gravity Forms for Vehicle Make and Model Selection according to sample. We already created SIMILAR form in Car dealership sites, If you like I can show you through freelancer chat window.
I have extensive experience with Wordpress, PHP, MySQL, HTML5/CSS3/jQuery, I am also expert at theme development, plugin development, PSD to WordPress, customization of WP core for development of custom modules.
Regards,
Kaushal