Auto radiator in manual car

[evil_hitman]

Hi all,
I feel this is a dumb question but want to get a few peoples opinion.
I have just got myself a ke laser (manual)
The current radiator has a hole in it around the size of a fifty cent piece yet miraculously it doesn't leak coolant.

I'm looking to replace it but the local self serve wrecker has only got good auto ones, whilst new on fleabay seem to be all auto but advertised as good for manual.

Now I realise that on a manual I simply don't connect up the transmission cooler part, but my concern is the potentially unseen corrosion that may occur from the inside out in the trans cooler with no inhibitor (trans fluid) in there to stop it.

Am I over thinking this or is this a real risk?

This car is not a daily driver, it is a dedicated motorkhana vehicle so more than likely will only be driven on average one day a month and sit for the remainder.


Cheers
Matthew