This may be the worst Forza game yet. It's like they tried their hardest to suck all the fun out of the racing game. The entire mantra of this game is "built not bought" so they don't let you buy parts. You have to unlock parts. You do this by leveling up your car. Grinding pointlessly for hours per car. It's as if the developers felt there wasn't enough "game" in this game so they had to gamify the economy. Imagine if you wanted to buy grippy tires or a nice exhaust for your car in real life and the parts store said "no, you have to be a higher level". It's stupid.
Many of the car models are from older games. Some, older than others. There's a number of cars you still can't open the hoods on, and others where you can open them, but the textures under the hood just look wrong. Some cars don't seem to have damage models.
The racing itself is fun, but you get penalties whenever you bump anyone or go off track slightly. Also you are REQUIRED to take 3 practice laps for each race. It's frustrating and really pads the game out to make every race feel too long.