Dump or Repair?

I have a 2000 Chevy Venture with 128,000+ miles. I am told, by both a mechanic and the car’s computer, that the transmission is going. That said, its been going for quite a few months now. I bought it five years ago with 92,000 miles and have maintained it. Today, I was told that I have to put about $400 into the car (I don’t remember the exact problem, but the wiper motor and hub something have to be replaced). The car also has a sizeable rust problem under one of the sliding doors, the sliding door is moody, the CD player doesn’t work, and various small things are going. Given this, does it make sense to put money into the car?

The rust, more than anything else, is the kiss of death for this vehicle. Time to go car shopping.