Well my near-perfect streak with VW vehicles going back to 1999 was harshly ended Friday on my way home from work. The only other issue I had was the 'coil pack' recall issue on my W8 wagon in 2005.
Driving in regular commuter traffic, so generally low speeds, transmission in 'D' and not using manual paddles...I slowed to near-stop at an upcoming stoplight due to traffic backing up into the left lane to get into the two left-turn lanes...when the last car slipped into the left turn lane and I had about 4 car lengths to close to pull up to the next car in my lane at the red light, I started to press the throttle and for a brief moment the car revved a bit without moving, almost like it was in neutral...then a big loud CLUNK noise from underneath and I crawled forward, clearly not under correct power. Speed was around 5-10 MPH when this occurred. I was still at the light waiting for green so at that moment wasn't sure how big of an issue it was...but when the light went green and I went to accelerate, the car felt like it was starting in 3rd gear. And that's where it stayed - no shifts, just one gear...I could get up to around 45MPH max, with revs around 4500RPM...I was about 5 miles from home and 15 miles to the nearest dealership, and was in a part of town where I probably wouldn't want to be sitting in a broken car waiting for a tow...so I decided to try to limp it home. I stayed in the right lanes and could only push to around 45MPH most of the way - occasionally the car would get up to 45MPH then the throttle wouldn't respond at all, and I'd slowly decelerate to around 35MPh before suddenly the throttle would respond again and I could speed back up. At all times, the car felt like it had only one gear.
Once I got home, I went to back the car into my driveway, and the car made a big CLUNK noise again as I shifted into reverse. Reverse felt completely normal, but when switching back into D, the CLUNK again, and still only one forward gear. Called roadside assistance and scheduled a Saturday morning pickup to flatbed the car to the dealer...called the dealer to inform, knowing they wouldn't get to it until Monday AM. No fluids on the ground under the car, no metal bits or parts on the ground. Got a lift to the dealer this morning on the way to work, so I could pick up a loaner, and talk with the service advisor about the issue...now just waiting to hear what happened and what the repair and time will be. Hope this was just a once in a million bad-luck glitch - it can happen...but thought I'd mention it on the boards for info. I'll update more when I find out just what happened, and how long it will take to repair. I do hope the fact that the engine/driveline has been around in the Golf R, and the transmission fairly ubiquitous in VW/Audi products, means I won't have to wait a week or two for some part to come from Germany - I had that happen with the W8 Coil-pack thing because that was such a rare car here, the service took a long time. The Arteon is low volume, but uses parts and engine shared with other cars here, so fingers crossed it won't be too long.
The clunk noise makes me think it's not just a software glitch or something with the engine - transmission itself, linkage failure, crack or leak causing tranny fluid loss, torque converter issue?