This command not working even for me as Admin, is there a cure please?

What doesn't work about it? Any response?

Sorry for dealay and thanks for getting back.
I have tried again today, I can spawn the sedan but /clearcars is still "unknown command"   and can not remove spawned cars.  I have to Kill them as Admin.
Regards,
Dave

Hi, any update on this? I just installed this on my server and typing /clearcars does not clear the cars spawned with the /spawncar command.