You said you have "reinstalled the latest vehicle download", but nothing says you have *downloaded* now. If you are missing the 3rd cone, which is included in the current vehicle installer download, it means you are installing a file you downloaded before it was updated.
Maybe you haven't understood what the "July 2015" date on the button means, which is explained in the text above it, which says "Contains vehicles released after:". This means, in that installer, you will not find vehicles released "up to" that date, but AFTER that date, until today.
So, if you re-download it now, you'll find it contains the models you are missing.