I was going to suggest trying it in N, so glad you did. Do you think the frequency of the vibration changes at different speeds?
The frequency and amplitude feel similar, but with higher speed, it's more constant. Naturally with higher speed and depending on the road, you get more "natural" vibration from this type of road/suspension/wheels of the M3P, but this tingling/buzz vibration is different.
The thing that made the biggest diference, until now, was lowering the tire pressure.