Since you felt it would be tedious to explain specifics, you create a huge hole in our ability to give you a serious answer that is relevant to your situation. So to speak on a purely generic level, there's no such thing as too good a user experience.. The notion that you might make the user of your product TOO happy, or make their lives TOO easy, is the sort of sadistic logic that I would normally attribute to someone whose just shitty at developing user interfaces and wants some kind of perverse rationalization to justify their shortcomings.
However... this whole "flying car" analogy leads me to believe that you're not really talking about "user experience" in terms of user interfaces, ergonomics, and the like. It seems to me that you're talking about feature sets and what you are empowering the user to accomplish with your software. For example, some advanced text editors may enable global search and replace. That same text editor may support using regular expressions in a variety of ways. With this hypothetical text editor, it might be possible to combine the application of these features and modify dozens of critical files in unexpected ways, really wrecking the local PC.I'm wondering if this is the scenario that's really behind this question? If so, referring to this as "user experience" is misleading.
I'm fully in agreement that you want to be careful about what sort of capacities you grant the users of your application. If that particular feature has a crappy risk/benefit ratio, then drop it altogether. On the other hand, if you have powerful but risky features that you believe the software needs, then you should be working hard to improve the user experience in such a way that inexperienced users don't stumble across those features accidentally. Although I have personally railed against Microsoft's history of nesting options under multiple layers of dialog boxes, part of the intent there is to segregate "power user" options where they will not distract casual users from the features they actually care about.