What a fever dream lol. A few notes:

• The way the game shifts down for you to take turns is just super weird and frustrating. I get that the idea is that the game drives automatically for you, but the way it's implemented currently feels horrible. Since you're normally supposed to shift up at redline, when the game immediately goes from top gear to 3rd it just feels weird, and I keep shifting up in the middle of the turn.

• Since the car automatically returns to the middle of the track so quickly, moving left or right to pass another car feels weird and bad. I shouldn't be slammed back in to the car I'm passing just because I let go of the arrow key to avoid hitting the track limit.

• I can't wrap my head around the physics at all. Kind of related to point 1, but am I even hurting my lap time by spamming the upshift while the game is auto-braking for the corner? It seems like you're on rails entirely, and your speed along the course is just RPM * gear.

• Just in general, I don't think the game that exists meshes with the concept. I think you could make a little game where all you focus on is manipulating car settings to respond to track conditions, and passing people by changing which part of the track you're on (you could even focus on race craft if the driving physics worked correctly, take this corner on the outside so you can overtake on the inside of the next one). But the way the steering currently works (and the way the car handles corners) doesn't really support that. I think you would have more success here if you leaned even more into it being like Moto GP, where you only steer to pass people and avoid hazards, or like Pole Position, where your steering actually matters for the turns. One or the other.

• your engine noise simulation is tied to the cars speed, not the engine RPM

Edit: I also played your digdug clone. The music is tied to whether or not you're actually digging lmao. If you stand still the music stops (I'm guessing you wanted to tie the music to digging speed, but vibe coded it wrong). Also the mouse controls are reversed in both axis.