Heinz, I get a similar situation with my Plus8. The air intake sucks in underbonnet air and only points generally towards the side louvres.
I measured air temp using my OBD meter whilst on a run.
Ambient air was 15 C and incoming air got to 35+C.
Very little room to work a cold air source from the cowl area. Big engine and ancilliaries block everything off. Even shielding would be difficult due to space and closeness of parts.That side intake system looks ok, shame the louvres on my car point backwards, forward facing might help air getting in, or channel front of windscreen air past heater fan box.
Theory says that every 7C reduced gives about 1% extra bhp. Decent return for low cost mod. I reckon 5 bhp would be straight forward. I am not in the mindset of chasing bhp but would consider improvements without major work. In essence, reduce effects that bleed bhp. I used a shoebox to form an intake to shield air and that looked promising, Heat-Robinson effort but it gave encouraging results.
