1. Is there still availability?Yes. You could safely leave it to a week or so before the event.
2. Do we need to pay in advance or just cash on the day? In advance
3. Do we have to be there at 8.30am, or is 9.30ish OK so long as there's time for the scrutiny by 10am?9:30 is pushing it. I'd get there by 9 at the latest.
You need to have your paperwork checked before scrutiny, and have the car ready-to-run when you take it to scrutiny (i.e. all loose objects removed from it)
When you're competing, you'd normally remove the spare wheel too. For this day, it's up to you so long as it is firmly secured in place.
There will be a queue for scrutiny, so rocking up at 10:00am won't work
4. I have an extinguisher, but don't want to bolt it to the car - is there any way of attaching which will meet requirements (eg. cable tie /glove box)?No, it must be firmly secured, so it's accessible, and won't come loose in a collision. Cable ties will not be accepted.
If you ask nicely, you can borrow my bracket, which attaches to the two bolts on the front of the seat mount.
5. Are there likely to be helmets available to borrow/hire on the day?There will be a couple of loaner helmets available.
6. Can you have 2 in the car at the same time if the 2nd person isn't an instructor (eg. Dad - I think he's done Rob Roy in the past)No, but if your dad has a CAMS speed licence, he can sign on as an instructor, then it would be ok.
7. If it's not timed, is it still one car a time around the course? Do you get to go more than once?Yes. It's exactly the same as a full event, just the clock won't be running.
One car on the course at a time, and you should get about 5 runs.
8. If I'm required to keep to 80% of my maximum speed, does this mean I'm permitted to do about 176kms/h? 
That's a judgement call. You're just expected to be a little off your maximum pace, so there's less chance off you hitting the Armco.
