I picked this off the Benzworld.org forum that some of us Unimog guys use. We have had our fair share of scoundrels as well. I did not write this but I believe it is helpful.
"Here's a few ideas:
1)Most of us have access to a few megabytes of web space though our web provider; use yours. Make a simple page describing your sitiuation, load up the metadata with mog related keywords and the business name, and link from it to as many relevant pages as you can. Don't be so openly hostile that there is a serious worry about libel (if that is a concern in your location) but make sure the point gets across. It wouldn't hurt to know exactly what the slander or libel laws are in your area.
I'm thinking that having many keywords like "unimogs for sale", "unimog repair", "unimog resellers", etc... , might get your site ranked high enough on a related search to be seen. Also link to known good mog vendors, and highlight their respected status; not only do better guys get support but it also helps spread the word by comparisons about problems like this guy.
2) write blogs about your experience, documenting the issue as accurately as possible, and link them to the previously created page whenever you can. Blogs are often free, and you can cut and paste a story into a new blog in seconds as well as update it easily.
3) put a link to your pages in the taglines of your forum nicks if possible, with the hope that other users will follow and also refer to your story when they field questions about where to get a mog. This borders on annoying to many webmasters but in the mog world you might get enough sympathy to be forgiven."
I hope this helps someone. I have done research on companies, people and have personally found several blogs about a product/person that I was interested in buying or doing busines with. But it was not what I thought. Thanks to people that took the time to document their dealings, it keeps others from getting hurt financially.
