My advice to clients has never changed: NEVER BUY SEO FROM YOUR WEBSITE PROVIDER!!!
First, what did they tell you when they sold you your site? Was it something like "We provide the most search-friendly websites out of the box"??? Then, why are they now asking for $2,500 per month for their super-duper-premium SEO?
Second, you cannot serve multiple masters when it comes to real SEO. If your website provider is also providing SEO to 32 other sites in your market, how can they all be optimized for the important keywords?
Finally, the VAST MAJORITY of the premium "SEO" they do provide is absolute garbage (like the examples already provided on this string). Yes, MOST independent SEO companies also provide absolute garbage optimization, as well. The difference? I've still never seen good, honest, SEO from a website provider that was also cost-effective. I have seen this provided by a couple of independents.
Oh, and not every dealer even needs to pay for SEO. Google is pretty smart and most every dealer site built today is relatively search-friendly.
Queue the angry website companies to blast me here. (There's a reason they don't include me on their Christmas Gift Basket lists.) (BTW, I'm always happy to hop on a webinar with any website provider who wants to show me their premium SEO and why it's worth paying extra for.)