for a temporary hold on the model you can use goop clear plumbing cement. just clamp or hold it in place a couple of minutes and you can continue on. you can just peel it off if you need to and start over with no mess at all. i actually use this on all of my models for both temporary and permanent holds. you can get it at home depot or Lowes for about $4.00 tube. blue tube usually in the paint dept. goop also makes clear craft glue which is the same thing just costs more.lol this stuff works on metal or plastic with the same results. this might not be for everyone but it works for me.
i have seen real cars parked like that where i live.lol when i go to shows i have to move a lot of models so i bought some clear stackable containers from wallmart and made dividers for the models you can fit a bunch in those and stack'em up i usually put the hardtops on the bottom and the convertibles on top using a piece thin soft foam to separate the top cars from the bottom. i get between 16 and 18 in each container,