One is faster with increased difficulty.

Upon winning Arcade Mode, one can go again on higher diff., a certain amount of money is kept for the next run, and one can upgrade one's kart before starting the run. Moreover, when beating it on hardest, one keeps even the upgrades during the previous run.

I think this is the intended way to beat the harder difficulties. I don't think it's possible to make it through Germany on hardest diff. without any upgrades.

My question now: should this even be allowed? Since the setup for a run becomes a great hassle (beat game on easy -> normal -> hard -> (repeatedly beat hard until all upgrades unlocked and enough money to buy boosts) -> start run.