The front tires rub or catch on the steering link during tight turns. This hex shim spacer will space the wheel out 1.2mm so this doesn't happen. You will need to print 2 of these. I see no reason for using them in the rear wheels.
Filament: PETG (PLA should be fine too)
Layer Height: 0.20
Supports: no
The author hasn't provided the model origin yet.