measure how much space you have in your car and note where you want the inlets and outlets then bring a measuring tape to the junkyard and go from there.
i did about 8years ago,brought home a (dont laugh now) radiator from a 90´s 4cylinder ford escort with automatic transmission.. ok stop laughing im honest about this, just had to cut of a couple plastic mounts form its tanks and invent a way to mount it,worked great with a pretty tall filled 340 on the street.