On other cars this is a classic symptom of tired transmission fluid. I have not heard of it being a problem on Contiques though. On other cars it is torque converter chatter and is usually resolved with a very thorough trans fluid flush. The friction modifier part of the fluid has been depleated. Sometimes just adding friction modifier will improve the situation, but it is only a short term answer. In severe cases, the torque converter must be replaced.
I would say that a trans fluid flush is in order and then see if the problem still persists.
