Hello,
Ever since 1.7.16, possibly as far back as 1.7.15 or 1.7.14, I have been noticing that vehicles have been storing on plugin unload or server restart even while having the config setting...
"Store Vehicle On Plugin Unloaded / Server Restart": false,
This was not an issue before these last few updates, the vehicles used to stay spawned in the world.
Please check into it and fix when you are able to, thanks :)