Many car models use vinyl "polycaps" to affix the wheel to the axle, this allows the freedom to rotate, as well as remove the wheels whenever required. However, the pin on the wheel that goes into the polycap usually fits tightly, requiring care not to break something else when putting them on or taking them off.
I found that using a little liquid dishwashing detergent makes a great lubricant, and it is safe as it will not react with the plastic or poly.
This also includes aircraft, and any other model that uses polycaps for various functions.