I have a 20 year old Honda Accord. It’s been great, but the transmission is failing. I would love to get about 6 more months out of the car. I am only doing about 500 miles per month. My mechanic just flushed the transmission, put in fluid, and changed the in-line filter. I know I should have added Sea Foam Trans Tune during the process, but I didn’t. So . . . should I just add Trans Tune now? The fluid is full, but I suppose I could drain some off and then add. Please advise.