When you say "dealer" to you mean "BMW Dealership" or "used car lot"?

I basically have three flavors of used car sellers:

1. Dealership for the marque (ie "BMW dealer")
2. Used car lot. (includes: High End Luxury Car retailer, dealership for other marques, travel trailer on wheels on a lot with used cars...all the same_
3. Individuals

I *trust* none of them. I assume the dealer for the marque has more knowledge, but still dont assume they do the right thing. The are, after all, used car salesmen.