Putting my shopping list together to do this on the Proton. I've been getting the bad shift as well for a couple of weeks (not very consistently yet - just once or twice a day).
Looks like total bill for the job will be less than $200 (all 5 solenoids, both pan gaskets, filter, fluid).
I'll try to take pix & write the How2 in case anyone else needs to follow suit.