CRX probably doesn't meet his cargo needs.
Golf / Rabbit diesel?
Aside from another TDI, I'd suggest a used Prius. It'll meet or exceed your Passat's fuel economy. Meets your cargo needs. Doesn't meet the flat towing needs (must be towed with front wheels on a dolly). Not sure if you can get an '04 for <$8k anyway.
Moving on from diesels & hybrids, what I'd probably look at a manual shift Corolla or Matrix/Vibe.
Not sure what the last year of the Corolla wagon was...
But you'll find a number of Matrix/Vibe modders here on the forum.
Just some quick thoughts fired out there.
"only 343,188 miles on the clock" made me chuckle
I bet a well cared for Prius/Corolla/Vibe/Matrix will do the same.