I thought I'd post a pic of my pre-rad install.
Yes, it looks like a plumers who is paid by the meter did it, but due to the entry/exit points of the pre rad it actually works quite well. Having the extra length allows the system to hold more water so even less likely to get heat soaked.
Here is the pre rad, laying flat in the front of the wing just behind the bumper, with the fan ontop sucking cool air up from under the car through it.
Here is all the pipework, it is routed to avoid sharp bends.
I think it needs a diagram to explain the routing. That may follow?
The pump draws cold water from the pre-rad, the out from the pump is slightly upwards so that no air collects in the pump, then the water is pushed back to the CC and returns to the pre-rad for cooling. The pump is near silet, but that fan is quite noisy, I'm told it is a mini item (ebay bargain for £6).