I always put my hood up when it rains- keeps my hair dry
When walk 'round the front of the car and I feel that heat I often think it'd be a good idea to raise the bonnet/hood, espcially as there's the protective panel underneath aswell keeping that heat in. My neighbours would no doubt think I'm weird. Then again, they probably already think I'm the 'strange Brit who spends half his life under the hood of that mercedes'
If I had a garage I'd do it though.