Car, tanks, trucks, bicycles, trains is possible setting wypoints in mission using FMB.
People are only static crew in vehicles - to see then it's need change humans=0 to 1 in conf.ini.
But in the two last oficial patch the roads embebed on map are broken, now cars are not able to cruise over road,
they go sideways 3-4 meters and dont cross bridges, are a invisible "barrier" at end of bridges.
Even when you set waypoints manually the roads tends "capture" the vehicle if he go near.
Al vehicles move at same speed, and use the same engine sound.
Trains work better, but stuck on some bridges too.
This related tutorial (in Spanhis) maybe are useful:http://www.escuadron69.net/v20/foro/index.php?/topic/49119-fmb-anadiendo-carreteras/
Anyway it's fun set tanks battles in open field.