Some events only need an organiser to set them up and a small amount of help "on the day" to run. GRR would fit that category, attendence at shows too probably.
One could get quite carried away at car shows: the likes of Biggar, which is basically a lot of static cars on show, then one gets a few
victims volunteers together, park the cars up in a group.... and then chew the cud; browse; amble; and generally sit back, relax, and drink coffee (lots of coffee, from recent experience)
One can up the anti, and put up a gazzebo: get fliers made, and have some club membership forms, a few spare issues of the club mag, and spread out a display to entice new members
For the more "selling" sort of show (like Knockhill or Lanark), then get a DVD made up showing all the things the club does and take a telly & show the DVD...
but in principle - I'd reckon there's even less paperwork for car shows than for the stuff you put on through the MoD or the Forestry Commission!