Performance Customization
This game is amazing in terms of visual customization, but it falls short in performance. Being forced to use an engine swap that entirely changes the sound of the car to achieve 1500hp isnt only unrealistic, it absolutely goes against the idea of it being a sleeper car.
A lot of the stock engines that these cars have equipped from the factory have forged racing blocks. Take Millers Racing Engines for instance, or Late Model Engines. They use the same blueprints to produce the the engine with better materials and quality assurance, to ensure it can handle boost. That's how those 4000 horsepower drag cars still use engines under 500 cubic inches.
We bought the game to use the cars we love with the engines we love. That may mean sometimes we enjoy the different sound of the swap, but for it to be the be all end all for some cars to achieve 400+ kinda sucks and feels pretty restricting.
It feels even more restricting when cars like the RSR and Golf exist. I just dont want to have to use a forged V6 in a 77 Special Edition Firebird to achieve 1500hp, we dont have to drop two cylinders in real life to do that.
TL;DR - Engine swaps are restrictive, dead giveaways to sleeper builds and STILL cant compete with the RSR despite possibly changing the sound we love to achieve said performance.