Have just been out in the garage and had a go at fitting and removing the wheel.
When the splines are perfectly lined up it slides on beautifully all the way, when not lined up and i push the wheel on it goes on enough for the wheel to stay on and needs a good pull to get it off, it would be possible to drive the car in this state but obviously not safe to do so!
Because of this i have to make sure the steering lock is on before i remove the wheel so that i know exactly the position to have the wheel when reinstalling.
Theres no positive feel to the splines being lined up when rotating the wheel so have to make sure its lined up before attempting to push it on, maybe mine is slightly damaged? Its been the same from new.