I don't really get, why people would be upset about the 20 million cap.
I mean, there is no need to save up your credits, it is only there to be spent.
Because it makes no real sense. Sure, the Gran Turismo Fanboy Defense League will always be there to rush to the game and DP's defense with bullcrap excuses for why a 20-mil cap makes sense and is a good thing, but of course it's just ignorant bullcrap.
There really is no logical reason to pick that arbitrary number as the maximum. If you buy a Ferrari 330 P4, that's all of the 20 million credits gone, and you have absolutely nothing left over for even as much as an oil change, let alone tires or any other sort of upgrade if you so wanted. Now, again, the GTFDL will spring into action to suggest stuff like simply spending a few minutes on a quick race to get the cash to get the oil change, tires, and whatever else you want, but we shouldn't have to work around a ridiculous limitation in the first place. That would just be a way of dealing with a retarded limitation issue, and not actually fixing the fact that it's retarded and unnecessary.
As for there being no point in saving up credits because they're there to spend, if we just go around blowing credits all the time then we're not saving up the 20 million credits (or similarly high prices) for some of the most expensive cars. To get some of the cars legitimately means saving up credits and not just blowing them all the time.
Let me paint another illustration. You're saving up money for that 330 P4, GT40 Mark IV, or whatever other super-expensive car. You're almost there, with like 19,600,000. You decide to do the Expert-level Gran Turismo All-Stars championship in B-spec because it's next on the to-do list and you're getting those final credits you need. Bob wins all five races in that championship, at 52,800 CR apiece, and the 264,000 CR bonus at the end, for total winnings of 528,000 CR. That gets added to the 19,600,000 you already have in the bank, but you can't have 20,128,000, so you just wasted 128,000 CR. It doesn't matter if it's no big deal to get them back, because it stinks to just throw them away in the first place for no reason other than the fact that DP is mentally-challenged. They shouldn't just vanish into a black hole at all. Waste is waste, and this is senseless waste for a senseless cap.
There are no benefits to a credit cap. There are no winners with this credit cap. There's only losers.