We gotta remember that salesmen (oops, salespeople) are just that.... they are salespeople...... they sold themselves into the job, they sell someone a car. They have a gift and it doesn't necessarily mean they know what they're talking about.
The best way to approach this stuff is to page through the owners manual (something the salespeople rarely do) to see what was missed and what was crap.
Case in point.... the new Freestar comes with a space-saver spare...... if you have a flat, the original tire wont fit in the undercar well. Ford has included a small cable to secure the flat in the rear of the van - to prevent it from becoming a misguided missile in a wreck. I have yet to meet a salesperson that either knows the cable is there or knows what it is for..... and we are talking "safety issue" here.
BTW.... if you know something the salesperson doesn't, use it wisely, you might be able to throw him/her/it off their stride and come up with a real coup....