There is also an Ad Hoc multiplayer mode where you can take part in four-player wireless races or trade cars. There are a few race modes for local wireless, including a couple of ways to accommodate different skill levels (staggered starts and adjustable car performance), along with several options for the host to help keep things competitive (giving cars that fall behind a boost) and fair (punishing players for collisions). You can also fill out the field with AI cars or employ an AI driver on your behalf, whom you can level up by completing races in single-player.
However, that limit of four cars per race is true throughout the game, so it never really feels very populated - a sensation not enhanced by the absence of any online options. Perhaps online racing was a bit much to expect (although others manage it), but what about leaderboards? Drift Trial and Time Trial are crying out for them.
This will be a particular issue for people who struggle to find local competition, because there's limited fun in racing against your own times, and the CPU-controlled cars in single-player are thoroughly boring opponents. With no damage modelling or penalties in this mode for ramming, you can bully other cars out of the way on the first corner and then stay ahead without much difficulty. When you come up against speedy foes, they telegraph manoeuvres, stick to the racing line and make little effort to protect themselves while cornering.
The result is a game that by any reasonable measure is absolutely rammed with content - 800 cars, 35 tracks (most of which can be played in reverse, and several of which have multiple layouts) and a decent amount of tuning options (nothing like a full GT game, but enough to make a difference) and gameplay scenarios - but which feels awfully slight. It's especially galling because Driving Challenge gets better and better while it lasts. The idea of taking world-famous corners (like Nurburgring's Carousel) and making a short task out of them, giving you medal-winning times to compete for, could fill out as many challenges as you get in the whole mode. Instead you get half a dozen examples of each of a few good ideas and that's it.
You could argue that you're getting all the content you could possibly want and are then invited to explore it without restriction, and it's certainly possible to enjoy the game like this. I've lost countless hours over the weekend hunting down slippery sports cars, turning off all the assists and fiddling with Quick Tune, and then pitching them against hectic circuits in Drift Trial, my particular favourite.
But structured single-player career modes are more than just fuss; they're a way to regulate difficulty, excitement and choice so that the player gets just enough of each on an ongoing basis. Relying on players to make their own fun is either lazy or foolhardy. Coupled with archaic AI and the isolating absence of PlayStation Network support, this makes for a game that feels unfocused and regressive, despite its considerable technical and mechanical accomplishments.