Toe in is used on cars because the tires will tend to pivot outward slightly as the car moves forward. Too much toe out will aggravate the situation and tends to make the car wander.
For an airplane, it all depends on the landing gear design and geometry. If a plane's axle allows the wheel to pivot outward under load, then adding some tow in should help keep the plane tracking straight. Probably none of this matters if your runway is grass!