My 2008 335i seems to yaw or wander on less than perfect freeways, almost as if the car is following trolley rails or ruts. The effect is slight but annoying, I suspect the big shoulders in the run flat tires. Anyone else notice this?

I don't think it's the RFTs, I think the car just lets you feel the road better. What car did you have before this?

many different cars including a 318 I drove all over Europe but none felt like they were going off on their own.

At first I felt like the car floated and moved around more, but honestly with a little time I got used to it and now I feel that when I think about moving the car does what I want. It's connected, maybe more than your 318...I don't know. "tramming" is more a result of tires than anything so I guess it could be the RFT, but I think if you give it a month you'll get used to the car. Or try swapping tires to see if it goes away.

I have not noticed this with my car. Typically this type of behavior comes from a car with a lot of bump steer, Vipers are a good example. Do you have Active steering option, maybe the wierdness comes from that?

I've never really read about a viper with bumpsteer...lots of times it's because of super wide tires grabbing everything around.

I was getting some wandering with my tires on uneven road surfaces. I double-checked my tire pressure, and all my tires were low by 6-8 psi! After I filled the tires to the proper inflation, the wandering went away.

One possibility is to double-check your tire pressure.

That is normal with wide tires and bad roads. There is even a name for it, it is called "tram-lining". You feel it most on roads the experience lots of stop and go traffic as the asphalt deforms due to the static weight and forms kind of a wide grove. The wider tires follow those grove. I usually only notice it when I switch from the narrow winter tires to the wider summer tires then I get used to it.

On long trips it becomes quite tiring and even nauseating as the car twitches from side to side. Hands off the wheel has eliminates an operator malfunction as the cause.

On long trips it becomes quite tiring and even nauseating as the car twitches from side to side. Hands off the wheel has eliminates an operator malfunction as the cause.
Talk to your local representatives to get the roads fixed. It is really not the car's or tires' fault.