Maybe I'm behind the times here, but I just stumbled on CarTest 2000, and it's about the coolest thing ever.

It simulates automobile performance based on car specs, most of which are available somewhere online for most cars you can think of. They've also got a large database, but I've yet to purchase the product (despite the fact that it's really cool, I can't really justify $35 to play with this), so I don't know exactly how many cars are there.

Regardless, I've plugged in a few cars based on online specs, and the outcomes of the performance tests are very, very close to what the specs say. In addition, you can run cars head-to-head to get a better idea of relative performance.

The Java demo works just fine under Solaris, so I imagine it will under most Unices in addition to Windows. But the demo only provides a few cars in the database and no way to add new ones. There is an old DOS version that's fully featured, but it doesn't have a very new car database, though it is possible to add new ones by hand (it doesn't understand the database used by the Java version, unfortunately).

I have no relation to these folks, but I just thought it was very, very cool.