The transmission fluid is added down the dipstick tube.
Total capacity is almost nine quarts.
Mopar ATF+4Mopar ATF+4
It is on the bottom of the fluid reservoir.
Use only ATF+4
It uses DOT 3
It is on the front of the transmission case, below the cooler hoses.
Any stop leak additive is always a bad idea. If you do add it, make sure the fluid level is correct when done.
Total transmission capacity is almost nine quarts on a 2000 Chrysler Town and Country.
The pump is behind the rear seat. You have to remove the seat back to access.
When you changed the Radiator did you flush the engine to remove the transmission fluid that the already mixed with your water in the engine block. If not that would explain the presence of the fluid in the coolant holding tank.
A 2000 Chrysler Sebring was not built with a cabin filter.