//I would be careful about "distracting" the dog in the car by giving it treats, doing tricks etc, it could just increase the excitement assossiated with the car and mean that the dog is being reinforced by giving it attention in the car (if that is in fact what the dog is after).//
true! could happen!
but CLICK/TREAT for calm behavior in a parked car, and then advancing to CLICK/TREAT calm behavior in moving car, is another matter, imo, than asking for tricks in a car. It's similar idea to kikopup's video on "Capturing Calmness" on page one.
//I make her sit in the floorboard. //
IF IF IF IF Missy is queasy in a car,(?)
the floor board might not help at all. In fishing boats, they say, "stay where you can see horizon, not inside the cabin", if you are prone to seasick, which is much like carsick.
64's dogs sound slightly different to me, than Missy, cuz Missy was calm in front seat facing fwd, which makes me wonder if it is mildly carsick. But, it could be Missy just wants att'n, who knows. but, i'd read up on "signs of carsick dogs"
or "managing carsick dogs" and rule that out, just to be sure. Might not be it at all, but, not too hard to rule it out, either.
It'd be interesting to know, what would Missy do, if Missy sat in front seat, facing forward, with window open, chest harness or leash to seatbelt so she can not jump out,
and passengers in the back of car. Just as a diagnostic exercise, to see.