Gt5p and UC2 have better shadows because time (and position of the sun) stay the same. This way a lot of the shadow calculations can be done on beforehand, stored in memory and used when necessary.
In gt5 the sun moves, shadows change a little bit every frame, and have to be recaclulated every time on the fly... To be able to do this they needed to downsize shadow quality.
So in short we pay some shadow quality, but we get the magic of dusk at Nurby. Taking this in mind I can live with those shadows easily.
PS: I am not a PD programmer, everything above are assumptions, but bigger and wronger assumptions have already been made in this thread