I guess you would be so very amased when taking a spin of any FR car in GTPSP from the cockpit on Trial Mountain for example.
Lack of GT mode - AKA Simulation mode - in GTPSP game has nothing to do with game not being simulation from terms of physics.
Although PSP hardware is just one of the most horrific hardwares when driving games are concerned, if you have ever played GT series on D-pad (AKA times before GT3), you will certanly be blown away how actual handling is great when driving on D-pad of PSP in conjuction with manual shifting.
Your hands will suffer after just half hour - at least I have that problems, but than I'm 33 so I'm not so young anymore - but trust me when I say that driving any road car with S or N compound in GT PSP is one of the best experiences you can have regarding actuall feel of driving.
GTPSP is far the most underestimated GT game ever but without any logical reason for any GT or driving fan in general. Game has design structure that perfectly fits to "handheld - play for an hour" logic, it boosts enormous number of cars and tracks and it have the most superior handling model ever seen in handhelds and beyond, comparable even with unbelievable amount of "big" driving-simulaton outthere.
And if you're lucky owner of PSP with video-output you can even enjoy it more when attached to SD TV set (HD will not do any good
)
In short, 30$ you give for GT PSP is far the best money you can invest in your automotive-love and driving-simulation love.
GT PSP is a great game. It has it flaws, yes, but those are so not important when everything is taking into concern.