The sports car analogy is accurate- unfortunately, many of the people you're reaching out to on Facebook would AGREE that sports cars should be banned because they are dangerous, harmful to the environment, and people can't be trusted with them!
I like the texting analogy:
You like texting, right?
I like my assault rifle.
You think you need a cell phone for personal security and peace of mind?
I think I need a firearm for the same reasons.
Why can't you just use some other kind of gun? No one needs an assault rifle?
Why can't you just make a call? It is a PHONE, right? No one NEEDS to text.
I'm not saying ban all guns, just assault rifles. Think how many lives could be saved!
I'm not saying ban cell phones, just eliminate their texting function. Think how many lives would be saved!
At this point, the person I'm debating usually is rendered speechless and walks away or logs off. Hopefully, it gives them something to think about.