Anthony,

Unfortunately, I have a lot less faith in used car salesmen than you do.
There is no doubt in my mind that one can develop the kind of trusting
relationship with a dealer that you and your dad are enjoying. Perhaps
living in a small community and buying all your vehicles from people you
meet regularly in church and the PTA is the key. When I visit the three or
four Ford dealerships around me, all I see is smooth talking, desperate
salesmen, who may be selling cars today and cell phones tomorrow. They know
that the only way to feed their children is to sell; no matter what and no
matter to whom. I was never able to obtain any useful information from them
and learned not to ask. If any of them happen to know something about what
they are selling, it does not show, because they prefer to play it dumb.

I still had some trust in salesmen when I was shopping for a used Crown
Vic/Grand Marquis several years ago. My first question when I saw one was:
"Where did it come from?" "I don't know", was the standard reply. "Can you
find out for me?" "We don't have this information", they all contiuned.
Newer models of those probably have standard ABS, but for the 96-98 vintage
at which I was looking at the time, it was optional. "Does it have ABS?"
Without exception, the answer was yes, for every single one of them, on
every lot that I visited. I popped the hood on a vehicle that looked in
better shape than others, and there was no ABS. "You are wrong", the young
gentleman chastised me with great confidence. Feeling generous, I asked him
to accompany me to the car that I was driving, and showed him what an ABS
control unit looks like.
After several weekends of frustration I stopped asking questions and just
jotted the VINs off the windshields, without even opening a door (no, you
can't tell anything about ABS from the VIN without access to a dealer's
computer, but by typing it into Carfax or a similar service you can learn
enough to not want to open that door at all).