The last time my family made the long, parched drive from Phoenix to Austin on I-10, we were in our 1998 Nissan Sentra, with its gummy floormats and cracked windshield, driver’s-side window that no longer works and its built-in casette player, a sad car for sad times. We were fleeing California and a recession that had ruined us. We went slowly--the Sentra had no other mode--feeling depressed and anxious, towards an uncertain future.

This year, we did the drive in an 2014 Audi RS7.

It wasn’t ours. None of these cars we test are. It’s all a sick illusion. Still, we had a $125,000, 560-hp sports machine to drive across the desert and back in our 2,000 mile family adventure. “Wouldn’t you have preferred a nice diesel?” a colleague asked. That would have made sense for a family road trip. So would a Honda Odyssey with a built-in vacuum. But instead they offered us a car that wouldn’t be out of place in Forza 5. My wife, my 11-year-old son, and our ancient Boston Terrier would feel the burn.

My colleague Ezra Dyer has already made an efficient and witty evaluation of the RS-7’s crazed drive dynamics and warp-speed 0-to-60 action. I also had my chance to push the car around its limits, and I can say this with certainty: It is the best commercial sports sedan out there, above the excellent but slightly wafty BMW M6 Gran Coupé and the excellent but slightly heavy Jaguar XJR. The fact that I can even begin to make such a comparison makes me want to punch myself in the face. There you have it. The Audi RS7, a light rocket, stands alone.

This wasn’t a track drive, it was a family road trip, a function that the RS-7 was clearly not designed to perform. But that’s what I used it for, and that’s how it will be evaluated here.

Fuel Economy: During our voyage, we averaged just under 22 MPG. At first, it was blowing gas, but then we stopped using it alternately in comfort and performance modes, and instead changed it to an “auto” setting, where the car automatically calibrates the engine to use either four or eight cylinders, depending on the situation. That helped extend the 20-gallon tank a lot, though it didn’t keep us from spending $300 on gas over the two weeks we had the car. Like a snooty lord, the RS7 only takes premium.

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Comfort: The RS7 is designed to be a leather-wrapped cockpit, not a limo, but there was lots of legroom in the front and the passenger floor was very warm and tastefully lit, which my dog enjoyed. The backseat seemed a little cramped, but my son never once complained. That was a first.

Drink Holders: They were too small, in the front and the rear, to hold a medium-sized coffee or a 16-ounce soda bottle. It’s sure sign that this car was developed in Europe by Europeans, with their stupid tiny paper cups of espresso.

Connectivity: The RS7 has a Wifi hotspot with its own password. This will, at some point, be available in almost all consumer cars, but for now it’s a novelty. The Wifi does, however, depend on a satellite. In major cities, we had a 3G connection, good enough for streaming video. Outside of town, we got 2G, which provided only the most nominal service. And most of the drive, through the desert where Wifi would be handiest both for emergencies and entertaining kids, was a dead zone. Am I complaining about the Wifi in an Audi sports car? Dump my dead body in the pool.

Also, the car didn’t have a USB port. The Toyota Yaris has a USB port. It did have a port with a built-in connector for some kind of giant Euro-phone, but that went unused. The car also boasts a magnificent Bang & Olufsen sound system that was great until my son discovered the dubstep station on satellite radio and we had to spend six hours listening to him say “drop the bass.”

Safety: We hit a huge snowstorm coming into El Paso, of all places, and another one in southern New Mexico. It was a freak. Trailers jackknifed all over the road. There were terrible accidents and no visibility. But the RS7 has an incredible all-wheel drive system and state-of-the-art stabliity control, as well as headlights that illuminate something like three thousand feet in front of the car, as well as both sides of the road. Using these superpowers, the RS7 gracefully skated through some sketchy ice conditions. I wouldn’t take it off-roading, and we probably could have used some snow tires, but it’s damn safe.

Smooth sailing: Conversely, on the way home, the weather was clear and in the 60s all the way, perfect driving conditions. We stayed at 90 mph almost constantly. The car pretty much drove itself. Cruise control slowed the RS7 down and sped it up, as obstacles came and went. And when it got dark, we discovered an infra-red night vision camera that helped us not kill wayward roadside animals. This infrared image came up on the dashboard, clearer than Zero Dark Thirty. It felt like we were driving KITT from Knight Rider. The car even looked like KITT, though it didn’t talk to us in the voice of William Daniels.

We pulled into our driveway after midnight. There sat the 1998 Nissan Sentra alongiside a Prius, our actual cars. But for a shining moment, we’d had an RS7, and it had given us an awesome road trip. Even without decent Wifi.