Thanks for the reply!

The preinit.d file (M50gpsapp) looks like this when I cat it on the player:
empeg:/etc/preinit.d# cat M50gpsapp
#!/bin/sh

[ -x /programs0/incar ] && /programs0/incar || exit
[ -x /programs0/gpsapp ] && /programs0/gpsapp

I gunzip'd and tar -xvf'd the file on a linux machine, so I believe the file should be OK. I also made it executable:
empeg:/etc/preinit.d# ls -la
total 3
drwxrwxr-x 2 0 0 1024 Jul 1 2001 .
drwxr-xr-x 4 0 0 1024 Jul 1 2001 ..
-rwxr-xr-x 1 0 0 110 Jul 1 2001 M50gpsapp

If you can think of something else I may have missed, I'd surely appreciate another suggestion!

thanks again,

Brian