Bring spare brake pads for the front.
Make sure all your fluids are topped up (not body fluids though)
Bring your own helmet (racing helmet)
Bring a little daft bit of wood to stick behind your wheel in the pits so yo can leave the handbrake off (even though its a seperate drum and not through the caliper
If possible, bring a jerry can of optimax since most of the scoobs dont like the hairpin below half a tank And it only takes about 15 laps to use that
Cant think of owt else