A road test of a 2013 MCS Hardtop I saw on the Internet noted the car on straight highway stretches had a nervous feeling ride and lacked resolute straight-line stability. The reviewer said the car felt unsettled beneath the driver's butt creating a bit of a nail biting driving experience and an urge to make ongoing, small correcting steering inputs on straight highway stretches. I'm thinking of buying a 2013 MCS.

Is this an issue with the 2013 MCS? Has anyone experienced something like this? If so, any thoughts on how it might be tamed?

 

I completely disagree. My experience is quite the opposite.

 

Yup, something is wrong. Alignment or whatever.

 

Check your LCA bushings and suspension components for wear. Does the car feel like it pulls you in a certain direction, i.e. you have to keep the wheel turned into the opposite direction to keep it going straight while on the accelerator? Could be due to tire pull/worn tires and an alignment issue.

 

Hmmmm.....
At 120 mph on the track, this would be quite noticeable...
Nope, never experienced it and glad I haven't.
The car is absolutely rock stable at highway speeds.

This problem could also be a result of belt separation on the tires.

 

I would look at wear items like control arm bushings, struts, tires etc. alignment too! One more area, camber plates, I've seen some put on opposite/wrong sides, yielding positive camber. Which is very unstable.

 

Yup the alignment is off and/or the LCA's are blown-out. The latter is fairly common in modern BMW's with >30k miles.

 

All the suggestions above about suspension alignment and wear are right on and should be checked.

However there may be a very simple cause - depending on the tires and road surface, sometimes you'll get "tramlining" where the tires follow the grooves cut in the highway surface. This was very noticeable when I got rid of the runflats and put on Michelin PSSs. The wife's Subaru Outback did it too with the old Bridgestones, it went away with Continental DWS. There's a few places on my daily commute where the grooves cut in the road are at a slight angle to the lane striping and I can feel the car move around a bit, the effect has diminished as the tires have worn.