WHY ARE YOU WEARING A HELMET? You are on a closed course (AKA a parking lot) doing burnouts/ donuts. Let me repeat that: DO-NUTS! You are not racing through hairpin turns on the Pacific Coast Highway or doing track testing at Nürburgring that could potentially end in a fiery crash.
Though you are in a Mercedes supercar, you are not Michael Schumacher (or any other member of the Mercedes GP racing team for that matter. So please, have the quiet dignity to remove your helmet the next time you undertake this type of low risk driving in an exotic car (or any car for that matter). Don't worry, a guardrail is not going to magically appear in the middle of the parking lot and sideswipe you. I promise.
PS: Going with the gull-wing doors up was a good move. It looks cool, plus it allows you to replace that "new car smell" with the only aroma that is even more pleasing to the senses: The smell of burnt rubber.