After driving either my '97 Dinan M3/4 or my '00 Dinan 540i Sport, I do what some friends have criticized as ineffective or even foolish. I raise the hood on the car I have driven to disipate heat from the engine. Also, I put wooden blocks behind both rear tires and take the car out of gear and release the parking brake to allow the cars weight to roll up against the blocks. Do these practices make sense? Do they achieve the desired results?