Only reason I say that is because Iceman did say Vehicles(s) which means at least 4X2= 8 test samples. I could see maybe 2-3 test samples out of the 8 pulling it off but 8 out of 8 would be a tall order.
He may be using those Hi quality metal tire valve caps w/ the O-rings in them. That does help offset leaking tire valves. I do find that those really do help.
Where can I find these?