also does not list the -b option

OK. On further inspection, there are two versions of netcat, both announcing themselves as v1.10:

The version that comes with Debian potato is actually version 1.10-12.1, and doesn't support the -b switch. This is the version that works on the car player.

The version that comes with Debian woody is actually version 1.10-21, and does support the -b switch. This is the version I was using on my PC.

The woody version will not work on the car player without some work, since it requires libc-2.2, rather than the libc-2.1 that the car player has.