jeepas creepas, where'd you get those peepas.....
what version of flashpoint are you using? i was told that in earlier versions you couldn't tell an AI vehicle unit to go someplace by clicking the map in-game without also telling it to start the engine. i have no experience of this, as it always works fine for me, without an explicit "engine on" command.
are you assigning the solda as a driver
before you get him in the jeepa?
sometimes if a waypoint is very far away an AI will take aaaages to decide how to get there. is the waypoint far away? are you giving the solda enough time?
check the slider values on the jeepa. is there enough fuel?
it seems a silly question, but is the jeepa on a road? doesn't have to be, but if it's behind a bush or a house.... nah, it would still move then, that can't be it.
seems an odd problem, but then odd problems go hand in hand with mission editing. keep at it, and don't let it dishearten you. just imagine the feeling of elation the first time you'll see the jeepa move properly. it'll be like the birth of your first child. in a jeepa.