800 cars that have a blacked out interior view.
But apart from its shortcomings, you'd really want to play the game for the driving itself. The game offers a nice driving experience and with the huge variety of cars, it's actually fun to spot how one car feels different from the others and all.
Honestly speaking, I can't find any other game on the PSP that feels as great as this. Driving around real-life and the all-time favorite tracks of Gran Turismo is such a pleasure in this version, PD seriously needs to step up if they're ever gonna make a Vita version.
A lot of people have mentioned the lack of career mode as a bad thing but I personally didn't miss it and wish that GT5 had a similar mechanic. The problem with career mode is that it limits which cars are useful to you at any given time. Say you buy a 1960s honda for a specific race there may not be another race you can use it in. In contrast GT PSP games makes sure that you can use any car in your garage at any time because whatever you pick you will get similar cars to compete against. I agree with noobdrifter821 that this encourages you to collect cars and then enjoy driving them.
Of course for those days I couldn't decide what to drive I made a random campaign generator:
https://www.gtplanet.net/forum/showthread.php?t=124125
It's not bad. But not brilliant.
Graphics are between GT2 and GT3, approximately GT2.75. Sounds are good, diverse car selection and some good tracks on offer.
But, negatives for me; no career mode. You win money in arcade mode or licence tests and buy cars. That's it. There's also only 3 AI cars, which I find to be quite boring.
I don't have access to my PS3 at the moment, so I'm playing GTPSP heavily and it is a good game, regardless of it's simplicity. If you've got a PSP, it's worth getting.