Alfa romeo 147 door woofer adapter

grabcad

I designed these simple adapters to fit 5" and 6" commercial woofers on my 147 doors. For front doors, you'll need double the thickness, so use two adapters to avoid damaging the glass. These plug-and-play adapters can be installed without modifying the door panel. They probably fit other cars like the GT and 156 too, as long as they have the same original woofer - just measure the wheelbase of the external holes.