It was just going to be a simple Bosectomy / factory replacement but one of the Focal ISU200 woofers was dead out of the box. I already have the car apart, so
Colunas Audi A4 Focal ISU 200 - Car audio HiFi Upgrade 1din 2din
NC] Review of Stereo Upgrade w/ Focal ISU 200 - MX-5 Miata Forum