There are several potential issues with the car, and I need input on how to present them to the tech tomorrow in the most "strategic" fashion. One thing I know how I will present is the trans issue, whch I am simply looking for feedback on as far as a cause. There has been ongoing funny-ness with the 722.6, for example slipping a lot in first. The conductor plate was swapped and fluid/filter changed, but no change in behavior, then all of a sudden, 2 months later, it stops slipping in first except on rare occasions, and instead there is additional harshness from 1-2, 2-3, WOT downshifts from 5-2 and 4-2 produce a LOT of lag, tach all the way to 6k with probably 2-3 (1-1000, 2-1000, 3-1000) secs of waiting before it is in 2nd and accelerating. So, this is exactly what I plan to tell the tech, but do you think it's electronic or mechanical?

Things I need to know how to present. The car feels a lot looser than at 60k when I bought it. It has 75k now. I know this is not a 3-series, but I seem to be unable to stay in a lane on the highway, like I'm commanding a cruise vessel. There is a lot more up and down undulation going over surface irregularities, but I've never heard of MB shocks going this early. I can only get an inch or so of play at top dead-center, but if I rotate the steering wheel even a quarter turn, at that point I can easily produce 3 inches of play, AND I can hear clunking sounds somewhere in the steering gear or column when I hit resistance again. What is this?

The motor continues to "choke," dropping to 200 rpm and then immediately recovering, only after driving off and then stopping a short distance later, before the car has warmed up. It will cycle like this repeatedly, almost rhythmically, until I get going again. A sidenote is that it stops this "cycling" earlier now that the ambient temps have dropped for the season. There seems to be a direct correlation between ambient temp and this behavior.

Next, a slight but obvious rattle has developed under the hood, and all I can think is timing chain or tensioner. You can hear it with windows up when idling, when there is silence in the cabin. It's not a heinous noise by any means, but it's new and I'm concerned.

Finally, the dealer uses Rotella T dino, 15w40. I bought some in June from Sam's because it was a steal. I change oil every 5k regardless. The best indie in town says he either uses Castrol 20w50 or Mobil 1 15w50 year round, regardless of season. He advised I switch to the Mobil 1. I'm inclined to as well simply because of the better flow at low ambient temp, for cranking. I know the dealer will use 0w40 unless I buy my own. Should I just stick with the Rotella?