I was reading Introduction to Eletrodynamics by Griffiths and I see that´s nothing there about to prove the gauss law for charges in arbitrary motion and non constant velocity . So I try to calculate the divergence of the lienard wiechert fields to show that the divergence of the lienard wiechert eletric field is equal to the charge density but I am getting stuck in the calculations ! Somebody know how to do these calculations ???