I like the cars how they are, plus it kinda modernises them too much by tuning them. Let's keep the classics, the classics, really. It's not very arcade either, excluding the existence of the FaF cabinets and similar. (They're like an arcade racer where you pick a car and 1 upgrade, then you write down a code so when you play again you can use the same car and a new upgrade.)
Plus the whole tuning aspect creates a divide between people who can't be bothered with it, and those who are. Like in Forza games where the LEGIT leaders on each track tune their vehicles to perfection whereas lazy sods like me don't have a hope in hell because I just wanna dive in head first and race cars.
Plus it makes getting those faster times better when it's all you, not your Exhaust of Acceleration +2 or Legendary Enchanted Gearbox...if that's how those video games work I assume.