If you want to pump up tp 45PSI or so not to far away, you can just come down as needed. We have 12 volt pumps, and air tanks between us if you want to do it there.
A good tire gauge if you have it. If not, no big deal.
Leave as much of the crap like floor mats, and stuff in the side pockets etc. home. Same with the trunk. You will probably take the spare out before you run, but you can leave the trunk carpet/spare cover at home.
$50 should take care of your day including the event and some food, but excuding gas money.
Idealy, you would run with about a 1/4 tank of gas, but anything above that is OK, just don't fill up right before if you can avoid it.
A folding chair would be good. We have pop ups for shade.
Just come out and enjoy...
__________________
I am a Commodore PET --- Now get off my lawn you kids... 
|