Talking of ponies....mine's busted.....well it's 'ers actually and took a few days to find just where the coolant leak was coming from.....f'ing plastic tanked radiators !
New aftermarket one sourced today and fitted tonight with just a block flush required in the morning before hoses back on and fill with new coolant. Once I enjoyed this stuff but not so much anymore. 
Still, nearly 20 years outta the original in a Commodore VXII is not too bad for an alloy and plastic POS.
Managing to contain coolant for 20 years of vibration, temperature-cycling, dirt etc. without a leak is quite an achievement. Why is it a POS? How many other parts of the car failed or had to be replaced before it?
McBryce.
1) Alloy radiator core is approx 40% higher thermal transfer for the same volume in an engine compartment.
2) Plastic tanks are necessary to isolate the core electrically from the grounded body of the car due to clogging caused by electrolysis. This is also why we have the pink coolant.
3) The same electrolysis also clogs up copper/brass radiators unless they run their entire lives with only pure distilled water in them. It just takes a little longer.
4) Plastic/alloy radiators are 100% recyclable, and in a profitable manner.
5) Brass/copper radiators are full of lead, so not recyclable and ultimately a toxic waste product.
6) Most of the copper/brass automobile radiators in service for the last 3 decades have been recored... the only part of the original radiator left are the tanks, which you get NEW with a modern radiator.
The commonplace hatred for modern radiators is entirely misplaced; they are better all around. FULL STOP. The majority of brass/copper radiators never lasted any longer than modern alloy/plastic radiators... the difference is that ignorant dumbasses could patch a hole in the brass.
So, because you can't do a ghetto-fab fix with the aluminum cored rads, ignorant folks that live on booty-fab rather than proper repair hate them.
mnem
Ignorance is curable; dumbasses will not learn.