The biggest issue I ended up finding was the car’s length, and it was a bit bulky at the rear. Thus, it went back to the repair shop:

Of course, it’s far from perfect, and I feel like the sides and rear wing can be slightly improved on, but it’ll do for now. Thanks to Jedimario for helping me realize this. Even if it’s not perfect, this still looks like an improvement. Finding another build online certainly helped.