After you've used your R53 Cooper S
 

Once you've finished used your mini cooper s (supercharged) do you let the engine get some air/cool down first before you store it away in the garage. I tend to open the bonnet and let the engine/intercooler cool down and close it later on. Is this doing any good? or is it just a waste ?

Waste.

Are you doing this because of the old turbocharged engine recommendation to let the engine idle for a couple minutes and let the turbo spool down? This isn't applicable to supercharged engines (which have entirely different principles involved) and there is no reason to adapt any special cooling protocol whatsoever with a supercharged engine.

By the same token, I don't think you're hurting anything other than wearing out your hood release.

- Mark

no i dont let it idle, i just leave it to cool down as the bay is very hot after driving it.

Doesn't hurt anything, but really not needed.

After you've used your R53 Cooper S
 

As others have said, it can't hurt except maybe wear out the latch quicker.
What it will do is cool engine bay faster. That may prolong the life of some of the rubber and plastics parts.

And if it does nothing but make you feel better do it!

Hope this helps...

I always let my Turbo Charged motor cool to 300F or below but had a Pyrometer to tell me that too.

I do not let the Supercharged motor cool much at all. I normally do idle down for a minute or so while I close things up and check things though.

In the summer time when its hot I keep a big fan in front of the car when I get home i just turn it on, My Garage is under the house so I do this just so the heat does not make the house any warmer, and it does cool the Mini quicker but I dont think it does anything for the car

I typically just slow down and idle through my neighborhood, driving at slower speeds to let things cool down a bit. I also drive slow and mellow in the morning to let thing warm up in the mornings - particularly cold mornings.

dp