In this work a space-time discretization for linear hyperbolic evolution systems is introduced. A discontinuous Galerkin approximation in space is combined and analyzed together with a Petrov-Galerkin scheme in time. The idea of DWR methods is applied to derive a p-adaptive strategy. The full linear system is solved in parallel in space and time by using a multilevel preconditioner. Numerical test validate the efficiency of the method in case of linear transport and Maxwell's equations in 2D.