It's pretty - but there is a lot of heat underneath...
You're at the track - it's above 85F outside in the shade and you're wondering about what the temps are doing to your car's IAT and coolant temps in general...
The S55 has great thermal engineering - it's unlikely it'll be overly stressed temperature wise when temps are between 75 to 105F... but you're wanting to try to get every last extra BTU radiated out of engine compartment - might want to try removing the S55's top engine or beauty cover - BMW's own M2 CS Racing doesn't come with one, and from some preliminary FLIR / temperature measurements, there is a lot of heat right under that cover, just waiting to make a great escape.
Take a look at the M2CS Racing's engine compartment as it comes from BMW and you'll notice something's not there right away -
The S55's top cover is over a couple of things including a part of the cooling system and oil system - both a major source of heat in the engine bay..
While the cover does a good job of muffling the noise and sounds from the fuel injection system and other engine components, it's also one more layer escaping heat needs to get though to radiate out. This may be helpful in the middle of winter, or in cooler weather - but on the track getting the extra heat out may not be a bad thing.
The top cover is easily removed - attaches with a few snap-on points to the top of the engine - just don't loose it in the pits!