Take a close look at the Track Day tech. form, it states that an on board extinguisher is optional. At the link to Barber it states that a extinguisher in the pit of each participant is mandatory. It looks like you will need one in your pit but not on board.
It is always a good idea to have one on board that can be reached without unbuckling the harnesses.
2005 Lotus Elise (NA)
Summit Point Motorsports Park, Shenandoah Circuit 6/8/19
[Moderators - I posted this previously in another area of the site, but I think this is the more appropriate place. Please feel free to delete the other thread.]
This past weekend the two upper control arms bolts sheared on my right rear corner. It sent me into an immediate high speed snap spin. Looking at the parts, I think one of the bolts had started to back out, setting up a vibration and shear forces.
No serious damage to the car, but on several...