I just had a good look and a measure up and I would say with a little skill you could make a nice 120mm fan mod in the lower divide roof. . t SU and cage would have to be out for the fan to fit in and then there is the whole issue of how this affects the cases *two thermal chamber* design?
If I had two GPU's in that case and I had all the tools needed I would do that mod in a flash. Apart from that I can't see a better way to improve the cooling to the lower card in a two card setup.
You might get some inspiration out of my case, which is an el obscuro variation of the P180 design probably made by Antec for an OEM called Panrix (which I found out went bust in 2002, so this case has been knocking about for years now!
)
Inside the case when I first opened it, screwed onto the plastic divider separating the top and bottom thermal chambers, I found a weird plastic contraption (which may well be part of the standard Antec design, but I haven't seen it in any of the pictures you guys posted in this thread!), which at the time seemed to me to have no use except to hold the 5.25" drive rails:
I naturally removed it and stuffed it in a cupboard because it would block the bottom three PCI slots, plus you'd have one extra thing to unscrew every time you wanted to change something in the case. When I got it out of the case and turned it around, I noticed that the underside of it had what seems suspiciously like an 80mm fan holder:
My guess is, the position in which this thing was intended to be used wasn't the position it was in when I first got the case, but was rather meant to be fixed onto the divider at right angles to it, suspended in parallel over the motherboard like this:
What the pics don't show is that one side of this thing is open and the other closed, so I'm guessing the open side was meant to face the grille at the back of the case (well, at the back of MY case, I have no idea if the standard designs that you lot all have also have this... it seems a bit weird to me for a case to have soundproofed side panels and a grille at the back of it to let all the noise out!
). It'd be drawing cool air from outside the case and blowing it onto the graphics cards, sort of like a mutant test-tube baby grown from the cells of a Zalman bracket and a PCI fan extractor.
and don't forget once a GTX is in the case, you no longer can utilise the wind-tunnel.
so, p185 can be more improved version, with 3cm taller allow for higher motherboard, and 4cm more depth front to back, to allow for a bigger graphics card while still using the hard disk drive holder.
Hang on, you mean the top drive cage is intended to create a wind tunnel effect? I actually went and removed it! (only got 2 drives so thought I'd use the bottom one, to keep all their heat in the bottom compartment and because the drives and cage got in the way of graphics card installation)