Vibration after long drive

[Roadrunner143]

Car: 2007 Audi RS4 currently at 190k km carbon clean done at 160k km and JHM tune

After a long drive of 3h+ I have a vibration at light load meaning if on cruise control it feels like a wheel is off balance really bad. Ease the gas pedal and vibration goes away. Accelerate hard and vibration is not as bad. No CEL. If I stop for 20-30min and then back on the road vibration is still present at light load. It'sonly after a cool down overnight that it'sback to normal. I do feel a vibration under medium acceleration when driving everyday but not as bad as after 3h of continuous driving.

What could it be? Motor mounts (still on originals)? Intake flaps not cooperating (but that would throw a code I think)? Trans/diff mounts?

[Velox]

Sounds like a sticking/seizing brake caliper. Especially because the symptoms appear after extended drives . I had exactly the same symptoms with my old beemer.

[Roadrunner143]

So I should try hard braking to see if it goes away? Extended drives I experienced this don't involve lots of braking btw

[Striddy]

If not brakes, I would check your drive shaft assembly. From what your describing, I had the same issue with my 4Runner. Vibration under acceleration and it would disappear when I let off the throttle. It was the yoke assembly on the drive shaft. As I continued to drive it, it got progressively worse until repaired. If it was a brake caliper sticking, it would still be evident when your not accelerating. Check your CV shafts as well

[Roadrunner143]

And why would this vibration get really worst all of a sudden after 3h of continuous driving?