Actually Toyota did not have the Previa in 1988, but we understand what you mean.
I traded in countless Toyota cars and trucks with over 400,000 on the speedo. Stop by the Voss Toyota Store in Beavercreek, OH and talk to Jim the Service manager. He owns a Tercel Wagon with 415,000 on the odometer.
Yes, the cycle may appear to be short, but the reason lies in the fact that Toyota holds its value; therefore, owners can trade more often because they are not prone to that American disease known as "negative equity." You can trade a two year old Toyota and not take a whipping on value, but the Big Three's Iron doesn't allow you to trade with positive equity until about year four. Toyota owners trade off for another Toyota (Highest Customer Loyalty In The Automotive Industry) and the trade in goes to a third world country. I have a missionary friend in Kenya that has such a Toyota and it is about to turn 375,000.
Of course that is why the Big Three could not compete in the leasing market, because their products have very little residual value. In 2000 I was leasing Toyota Camry's for $199.00/month. A Chevy Impala would lease for $349.00/month. The math always tells the truth.