honestly speaking ...if this is a underbonnet heat problem one has to ask what they were testing ...when developing this car.
you will obviously run the thing under lots of different conditons and will know exactly where and when critical under bonnet temps are reached.... if it is in stopand go normal day situations it is something hugely unaccepatable and no manufacturer would be foolish enough to let expose his customer to a permant high risk situation ...if they would not test /check temps under these conditons that would be a indication of lack of expertise. which was even worse.
I see no reason why a mid engine layout should be a at higher risk than front engine layout.
Obviously the front engine will have more of a cooling airflow coming from the radiator fan(s) but this is an obvious thing to check in mid engien application if you´d still need to have an auxilliary fan to keep underbonnet temps in check,
something Porsche is doing with their rear engine layout since 996 days.
I think Audi has now added something like this to the R8 as well?
R8 pics engine/cutaway complete car look at the excessive heat shielding on the dyno ....