The Avin really saved my ass this weekend. I don't know if it would have been from a ruined tire or a full on crash, but either way it would have ended my track weekend.
Friday was all day open track. ~1 hour in a siren went off in my car. I glanced at the nav screen, and a warning as displayed that my driver rear was low. I switched over to TPMS view and could watch the pressure ticking down at ~1 psi/5 seconds. As I pitted in it was down to 20 psi, by the time I was able to stop it was down to 10.
It looks like someone lost one of those brake line retaining clips on track.
Inside of my tire:
I caught it early enough that the tire didn't get ruined. So, I borrowed a street wheel from another e46 m3 owner, drove into town, had it patched, and was back on track ~1.5 hours later. Don't know if I would have been comfortable with the patch, if I didn't have the tire pressure monitoring running with audible siren!
Great weekend, overall. Got to meet a bunch of M3Fers, and pretty much no traffic issues. BMWCCA puts on a good, if pricey, event.