Tags as checkbox in Custom post ?

Hi,
I have searched allot for plugins to make preadded tags as checkboxes, so no one can ad new ones to use those tags as options with checkbox whyle they are macing new post or listing, I am using WP 4.0 with sandora theme, specificly I am truing to add ”extras” wich those fools had made as tags ( I dont cnow what is the logick but any way ). The idea is my users when they post new car listing they can choose from tags (Cd player, wheels, etc) wich in the case are like extras tab. I have already installed few plugins but they are old and outdated, also all posts for that topic are old and nothing really works for Wp 4.0 🙁

If anyone can help with that it will be grate.
Thanks in advance.

Thats the page: http://karavana.bg/1/car/adria-club-330/

And the tags are showed as car’s ”extras” The tab is in bulgarian and its called ”Други”