The way I try to solve this is to ask "why?" as many times as it takes to get to a fundamental business problem. Then it becomes easier to have a user story (as opposed to a specific feature request) and come up with other solutions that can be measured against the story. It also helps to keep the product focused, as it's easier to tell when a story is not for your target market vs a feature request -- and then you can make a conscious decision to either stay away or deliberately expand to that market.

It’s difficult not to sound combative when they say they want a convertible but you have to wheedle out of them that they want to take a proverbial road trip through monsoon season. No, you get a Land Rover with a snorkel or you wait, pal.

So bossy and difficult. Why won’t you just give us what we asked for? These meetings would go so much faster.