I have not noticed this however i will take a look at my car when i drive it at lunch.

<font color=green> . . : : pestilence : : . .
2003.5 Infiniti G35 Sedan .... sports/sunroof </font color=green>

 

I've noticed this and have seen similar posts on the topic. Most
seem to believe this is normal. I've noticed that my engine gets
as hot as its going to within the first mile of driving and the
compartment is definitely toasty. No worries - hot engine, hot ride!

 

Its normal. They insulate the engine compartment so the engine heats up fast and cools down slow. Its a way of stabilizing the engines running temp.