You don't need to run a car radiator.
What you need is a junk refrigeration condenser and included fan. They are small and have very powerful fans. You then get 10-15m of pipe i use 6mm ID and mount the fan and condensor unit outside. A single d5 will be able to push that far but i use dual d5 in series. I guarantee you that this setup will outperform any overkill internal mounted setup and be silent.
I now run a hailea 1000a 1hp water chiller in place of the setup above.
If you want advice pm me.