The Trans Sport was sold from 1990 to 1999. The wedge-shaped body was based on the U-platform.
The first generation Pontiac Trans Sport was sold from 1990 to 1996. It had a selection of V6 engines and a 5 speed manual or 3 speed manual transmission.
The second generation Trans Sport was sold in 1997 and 1998, and it featured more conventional styling for a minivan. A sliding door on both sides was an option for those years. Another feature on these minivans was plastic body panels that resisted denting.
There was a higher performance version of the Trans Sport sold during some years called the Trans Sport GT.
This car has been criticized by some reviewers for its crash test results. It received a "poor" in the 40 mph test, with near full collapse of the passenger compartment. One dummy lost a foot in the test.
The Trans Sport Montana would eventually become the Pontiac Montana, which would replaced the Trans Sport in 1999. If you're looking to buy a used Trans Sport (and by now, they are all used), check out eBay first to get an idea where the market is pricing them. If you can't find them for much cheaper than eBay in your local market, you should probably just buy off eBay from a seller with a history of selling cars.