Extra Trial Cars
To get the extra trial cars at their best performance you need to beat them on expert.For example the utopia won't go 400mph unless you beat it on expert.
To get a really fast start, use manual transmission, then wait for the car to appear on the grid. Hold accelerate as quickly as you can after the screen appears. Now, as soon as the lights turn green, change up to second - your wheels won't spin and you'll shoot away from the grid. That's it.
Unlock all 320 cars in the game. Then the Pac-Man character, which can run at 252 km/h, and the Sony Eat'em Up car will be selectable in time attack mode.
Four player mode
Connect two PlayStations via a link cable. Then a "Link Battle" mode that allows a simultaneous four player game will appear.