Honestly, it's not a big deal, you weren't profiting off your image and it's not harming you in any way, so I'd just be happy somebody thinks you have a cool enough car for their website and let them use it. If you really have an issue with it, just find a standard DMCA complaint letter online, send it to the site's webhost and the webhost will force them to take it down within a few days, but it's not worth the time, just let it go haha.