If you are satisfied with just managing your inventory you could try a third party user (e.g. autoeasydms.com or something) for getting a website done. It isn't that great though in case you want more control..but at least it get's some work of your head...
This would defeat the purpose.
I mentioned earlier in this thread the importance of 3 factors. There are many factors that are important but those 3 are the most critical and they actually work together.
The main motive for a dealer needing to completely manage his/her own website is total control. This control allows a dealer to be able to constantly update content on that site. As you update content, google periodically crawls the site, taking note of the new/updated content. This tells the spider that it should check more often because there was different content than the last time. Here's a scenario
1 month deep crawl - Google crawls website finding new and/or updated content from last monthly deep crawl. Triggers spider to fresh crawl again in 2 weeks. Two weeks later, spider once again find new and/or updated content and triggers next crawl in 1 week, the 3 days, then 1 day, then 12 hours then 6 hours, etc....
The fresh crawls could come every few minutes depending on the changing content.
Each time your site is crawled, google checks backlinks. i.e. - who is linking to your site. The content relevance google found on your site plus the content relevance on a site linking to you and that site's pagerank help determine your own pagerank for various keywords. That's where keyword density in your content (among other things) becomes important.
The main thing here though is getting google to crawl your website as often as possible. The only way of assuring that is constantly changing content. While there are some methods of enhancing the pagerank with the backlinks, it really doesn't matter that much if google is only crawling your site once a month.
No 3rd party is going to do that for you.
Something to remember is that when you lay off a bit and don't update content a while, google eventually lessens the crawl rate and you have to do it over again. Also, iframes don't help you alot here. While it will be crawled, it only helps the page that's within the iframe, not the page framing it.