just give your char a bunch of tank traps and place them where you want your vehicle spawns, then get their locations from the instance_deployable table with your ID in owner_id
vehicles have no place in the missionfile, they should be in the database
I already reported this on Dayz Commander forum and so far he hasn't acknowledged there is a problem.
Go in your OA folder and delete @Celle and @Conflicts folders.
Restart your Dayz Commander, and install Celle.