U may find that although the plasic box containing the cooler unit is unique to the carina, the inner radiator part may be the same as other cars and is replaceable.
I saw a Carina Station Wagon on the street ages ago but swear it had a turbo badge on it or something suggesting turbo.
Sorry to hear, that sounds expensive.
The joys of imports.
If you have the part number, Toyota may be worth a try aswell. Sure it may be scary price wise, but never hurts to try. Just don't say its an import. just have the number and act real dumb, like you know NOTHING.
Try looking in NZ. I've had to replace the internal dash fan for my CT190 Caldina.
Search the internet.
Try www.toyotaparts.co.nz/
This is where I got my fan from.