Guys like any install, make sure you have all the proper parts BEFORE the install otherwise you'll end up tearing your hair out and taking shortcuts which lead to problems, such as popping hoses, punctured cores and bulging bumpers.
1. Purchase the RS4 IC Brackets, these are vital to mounting the cores like the factory intended. The Passenger Side (PS) will need to be modifed to work because the RS4 has the A/C accumulator mounted in a different position. The DS bracket can simply be installed with no modifications.
Look at the photos and compare to see where they are modified, I will take a pic of an unmodifed bracket later to help make the visual easier to see.
Start by removing the OEM brackets by carefully drilling out the existing rivets and modify the PS as seen. Then rivet the new bracket back into position.
The main problem with all larger cores is that the A/C accumulator presses up against the back of the PS core. We solved this by machining a small recessed plate with threaded holes. Then you simply drill one hole through the PS bracket and use another existing one, we supply the hardware. The accumulator has three holes in it, you need to trim off the top part to make it look flat and remove one hole. Then the accumulator can be properly mounted to the CNC'ed plate.
Hey look it's magic, no superconductivity, no they are just properly mounted =)
Here is a pic showing the areas that are trimmed in red. Rad shroud and fender tabs.
With Shroud installed
Money shot, almost ready to dance
The factory bumper needs to be trimmed, before
Not to preach but WEAR YOUR EYE AND HAND PROTECTION, TRUST ME!