radiators that didn't work

[caddy]

as a few of you know my bay has the radiator mounted behind the front panel .

previously to this i had tried out a custom radiator mounted under the front bumper, the same length and shape as the bumper but 3 cores deep.
the rad actually gave a massive overcool up to 30 miles /hour but then the temperature started to climb until boiling point.
the problem was found to be aerodynamics again. there wasn't a pressure difference across the radiator at speed , the radiator was only 4" high and needed a deep spoiler fitted below it to give a pressure difference.
we tried out a spoiler with good results, but not practical as the ground clearance was poor.

so are there any more tryouts that didnt work ?
_________________
1969 bay with vw 1.6td