Gran Turismo 1 through to 4 sucked at holding a drift. It wasn't impossible just took some getting used to, something I never really got the hang of. It was easy to cheat to say you did an awesome drift though...Photomode.
Forza 1 and 2 weren't half bad at it. I remember the rotary powered MX5 I had on Forza 1 sometime ago, that thing was extremely tail happy and was nice at holding it sideways round a corner.
As for GT5P, i've yet to try it out, but I imagine it won't be
that much better than GT4. More bling bling graphics than better physics by the looks of things. Maybe it will change by the time of the actual release of GT5, but again I very much doubt it'll be all that great. People buy it because of the looks, not the physics as its a console game.