I have played a lot of LEGO Racers, but also LEGO Racers 2. Therefore, I'm also known with AI behaviour in the latter game. Again, I give you a POV.
The AI for this game misses out in diversity of NPC paths. This is a factor that stuck in my head for years, and I'm none to pleased about this factor. LR didn't miss out on this, having multiple AI paths for each opponent on each track, but in LR2 they just all align to the same path, which annoys me. A result is that many power-up bricks remain unused, and in a row of four power-ups, only one or two are actually ever being used by NPC's.
To me there also seems to be a timer for the use of power-ups for AI's. Invisibility is always used instantly after grabbing, and a missile or some other 'red-type' power-up is sometimes used pointlessly (e.g. no one in sight, and firing the power-up). Back in LR, AI's would actually wait until they had someone in sight. Something else, the Destructabrick power-up makes you a bit overpowered, because only you can use it (unless an AI steals it from you). But giving each racer chances to get this power-up would prevail destruction.
But enough negative talk now. What I really like is destructible vehicles, it makes the bricks much more interactive in the game. The power-up system works out better than in LR. Where you could easily win after one or two warps (which is not hard to obtain), in LR2 the strength of the power-up depends on your position in the race. Physics are improved to become more realistic, but drifting hasn't been improved since LR. In fact, there isn't even a drift-button (or I missed something out here).
I can't summon all notable AI behaviour now, but I may be doing that in the future. Now I'm interested how others experienced the AI in this game, and if you know any other notable AI behaviour.