Thanks again for the tips Tony! I managed to find a working serial cable and just replaced the drive with a spare I had laying around. Plenty of space now, but the best news is that she picks up playing again from the same spot as when the car was turned off. I've only had it up and going for a day, but no "No hard disk found" errors yet. I'm thinking the drive I took out was just on its way out. I also had intermittent problems with the player freezing in the middle of playback.

Plus my ebay empeg was delivered today! We even have beautiful weather forecasted for the weekend. I guess that means I'll have to rip my girlfriend's dash apart and start looking into how to install it.