According to the law, no, you cannot legally remove a DPF from a car that was designed to use one. If you are doing lots of very short journeys in a diesel car, it is advisable to make one longer journey per month to allow the DPF to go through a re-generation cycle. When you come to change your car, consider a petrol powered one for city / town short run use. It won’t have a DPF and so it won’t be a problem.