Transmission

What is your question?

Occasionally, when I'm stopped at a traffic light and then release the brake and apply the gas the car seems to jerk/slam into gear. I presume this may be an indication of transmission issues to come. I recently replaced the spark plugs and would like to keep the car for at least another 2 - 5 years. Are there any suggestions on ways to prolong the life of the vehicle (besides don't drive it :) Thanks