When posts are deleted, it's because they break site rules. If you don't remember the rules, you might want to look them over again. If it's bad enough, you'll see a warning or infraction in your user CP with a brief explanation.

Most common causes of deletions:
-posting contact info
-asking/offering hookup of bud/seeds/clones
-discussing other illegal activities including but not limited to theft, assault, smuggling, dealing, etc.
-talk of other drugs or alcohol
-comments that are bigoted or otherwise offensive
-flaming another member or the site as a whole
Hope that helps.

Car talk should go in the hobby lounge.