I am truly impressed by your OCD.
Do you even have any idea how many hours total you've logged on GT5?
I have my concerns that GT6 may get the Forza 5 treatment, ie. SCE will cut the number of cars and tracks down considerably with new ones to be released as DLC as micro transactions.
On the plus side, if it is a smaller game by default, it should be faster for you to platinum GT6.