Has anybody mounted their radiator behind the front chassis cross members? This is because of lack of space for intercooler piping around the rad when the intercooler is in front. It looks like it might fit behind there, just in front of the CA18 engine.

I suppose the problem might be that it is then very close to the engine heat, and no longer ducted by the nosecone.

I did and as you say the most important bit is to blank off around the rad otherwise the air will go round it rather than through

Agree with last comment makes a massive difference reduced my car water temp by nearly 10 deg in a car I built about 10 years ago