I dont know why i got feeling that pd will upgrade all cars to premium .
I don't know why but I've got the feeling that simply won't happen, mainly because it's frankly impossible to do during GT5's lifespan and because they'll perhaps logically reserve a lot of Premium cars for GT6 so if we get some at all they won't be coming in massive numbers, maybe a select few to keep interest going (it isn't a simple upgrade, they have to start again from scratch).
Another thing you have to consider is that a lot of Standard cars won't be remodelled as Premium even for future GT's.
Given the amount of time and resources they take to build they have to prioritize and select their, well, selection much more careful and perhaps remove the 'redundant' cars.
Ofcourse that's subjective but I can't see them spending months modelling for example the utterly forgettable (in my opinion ofcourse) first gen Citroën C5 (which was current and therefor perhaps somewhat relevant in 2004, if only to please Citroën) when the current (and much more interesting) C5 is almost halfway its production lifespan.
And do we really need a Premium Opel/Vauxhall Vectra V6 when they could add its successor, the Insignia VXR/OPC instead?
So we'll probably be getting some classic/iconic cars which can be carried over into GT6, etc. whilst for the rest they probably return to the same procedure of selection they did when developing GT4 but obviously in todays context which means some Standard cars will, more or less automatically, return as Premium whilst for others GT5 will be their, arguably dishonourable, swansong.
)
it can't be from GT4, it's from GTPSP at least! 
