I remember engine compartment photos of the white E1a that revealed the primary engine radiator is already in a compromised position, mounted at a slight backward angle in order to fit beneath the sloping curvature of the hood.
Turbocharged Subarus are notorious for having top-mounted intercoolers, which in most automotive applications would be a less optimal position since heat rises and the engine case including headers is typically only inches from the hood. But Subaru's trademark horizontally-opposed Boxer engines are flatter than inline or V-style configurations, and mounted toward the very bottom of the engine compartment. Plus, picture any WRX hood and they all feature molded scoops to direct air cooling over the top-mounted intercooler. It's a common misconception that those hoods funnel free-stream airflow into an engine air intake.
Given the apparent lack of maneuvering room on the leading edge of the radiator assembly as it is, they either managed to squeeze a micro-sized intercooler application in just behind the front grille fascia but forward of the main radiator, for a contemporary front-mounted intercooler, or they're planning on resorting to a top-mount application similar to a Subaru setup.
Personally, I've always wondered if there was any room between the front grille fascia and the radiator to install automatic grille shutters for increasing highway MPG when cooling demand wasn't as pressing. With a front-mounted intercooler AND radiator in need of constant air flow with a front-mount intercooler arrangenent, you definitely wouldn't want to install grille shutters. If you did, it'd be at the peril of your purpose-built heat exchangers.
But a top-mount intercooler configuration would open up the possibility of installing active grille shutters, since I agree with Ekh that a 6+ quart oil sump should be more than adequate for cooling a 0.9-L engine.
Additionally, I would be itching for an aftermarket hood design that featured strategically placed scoops, channels, fins, baffles, etc for cooling the top-mount intercooler. I'm sure Roush could fabricate something impressive and mean looking!