[porschenut]

The RS front bumper accomodates the oil cooler just fine with the early front bulkhead, so that's going to be the easiest and most straightforward solution. If you really need a bigger oil cooler that won't fit, just cut a hole in the bulkhead so that the back side of the cooler can extend into the trunk area through the bulkhead. I've seen pics of that arrangement done by others. In fact, I suspect that will allow for greater cooling efficiency because air can flow through the cooler better without the bulkhead right up against the back of it.