Not the easiest of tasks in the A3, depends how far you want to go with it. Sometimes a simple add on dab tuner fed into the Aux input is the best way. Some people want better integration and you can fit an integrated solution like the AutoDAB or MediaDAB, if you have a USB port (AMI) you could also go down the Dension USB DAB addon route, but all of these need a good antenna to receive the DAB signal.