Todd, very nice build you have going. When I was looking at your cooling system, an idea popped into my head which I will try to elaborate on. Instead of using the flex pipes to make it possible to open and close the decklid, I think it would be trick to use Hydraulic 90° Swivels mounted below each hinge. These are used with hydraulic machinery and withstand something like 3000psi so that wouldnt be a concern. I'm not sure what size coolant hoses you are using, but they can make the swivels in any size I would guess. I found a few on ebay, the one in the pic below is 1" diameter.
If you attached a 90° elbow to that it would be 180° and would swivel as the decklid was opened or closed. Then throw some nipples on the end to mate up with the coolant lines you already have and it would be a pretty effective solution. The swivels themselves would probably need a small bracket attached to the outboard decklid hinge area to keep them stationary. Heres the link for the auction:
http://cgi.ebay.com/1-HYDRAULIC-HOSE-SWIVEL-90-DEG-ELBOW_W0QQitemZ260342492915QQcmdZViewItemQQptZPneu matic_Hydraulic_Valves_Parts?_trksid=p3286.m20.l11 16
This would probably take some trial and error to perfect but would achieve something great.