If you’re getting blasted with sand on the dunes or you ride through wet or muddy areas that splash material into the cab, you might be fine with half doors. If you do a lot of trail riding, however, and are constantly getting slapped with branches and overgrowth, then full doors are your best bet. Polaris-branded doors fit and work well, but they cost more and you have to buy both the upper and lower sections. Unlike some metal doors, though, Polaris doors don’t have many gaps and seal quite nicely. And many people have asked us if the RZR 900 doors will work on an ACE, but unfortunately, they do not and you’ll need ACE-specific doors. So whether you’re keeping the elements out, or the contents of your cab in, having that solid partition to separate your cab from the outside world is a must.