Mate that's a great lap but seriously, buy a lid. You have an off at that speed and those heads will be mush. Love the Spaz, rested massively by the few owners I know of.
It's a fair point but very few lids are worn on Touristenfahrten days. One person wearing a helmet would be pretty disastrous for other people in the car so it's really all or none.
The only person to actually crash was me, on the GP circuit.