I bought a double din kit + a loom adaptor from the bay and installed a more modern head unit. (It means bypassing the amp, which is a PITA to get to).
No cassette player now, so had to burn my 1980s Australian pub rock onto an MP3 thumbnail drive.
(I also installed a raspberry PI in the satnav pod whilst I was at it - it runs "crankshaft OS" and just mirrors android maps, but also reads info directly from a Bluetooth OBD2 adaptor)