There are NEVER rear mounted intercoolers on front engine cars, thats just bloody stupid. Tho have seen a couple of mid-engine cars with front mounted coolers.

But you will be suprised how little effect long pipe runs have on lag, dont believe the internet myth.

Rear mounted rads and oil coolers could work as well if not better than front ones if designed right.
Its not hard to get the ducting right so air gets to it and away from it easy, and the key to efficiency is having a TOTAL seal in and out the rad, something you almost never get on front mounted setups, so in effect you could get it a lot better than on the front.