Nitrous plumbing A1A...??..

Personally I would not pass up a good deal on a used bottle that doesn't have scars or signs of heat damage. Nobody seems to look at the bottle's cert date and if the track's tech guy did, he would probably be one of those guys also looking for the cert on the bellhousing/flywheel/damper/etc. Then there's those extra bottles in the trailer that completely skip the whole inspection process....

On second thought if you are at risk of a DOT inspection, it might pay to have that current bottle cert :)

Grant