Respawning Spawned Vehicles

Hi! I've had a dig around on the forums and I can't seem to find the answer to this question. Anyway, once you've spawned in your other vehicles, road signs and whatnot with the world editor, is there anyway to re-spawn them once they've been destroyed? For instance, you can press the R key to reset your player vehicle, is there any way to do this for all the spawned vehicles too? It's a bit tedious having to delete them all and re-create them every time!

 

Press Tab to change the vehicle. Then you can Respawn the vehicle and change back into your car