GM still makes the claim. TV commercials, magazine ads, etc. I've seen them recently.
Even the one bragging on the windshield wipers (seriously?) calls the car "the world's fastest production sedan".
"When you build the world's fastest production sedan, you consider everything. Like at 190mph, even a simple raindrop becomes a powerful force. The Cadillac CTS-V, every detail built for speed and performance, right down to the windshield wipers. We don't just make luxury cars, we make Cadillacs."
(I actually like the CTS-V and like the coupe even more but lies aren't needed to tell how good it is)