From my experience there are two types available, a sealed foam baffle/pod and a plastic baffle with a plastic hood.
Not all vehicles requires some type of protection on the rear of the woofers as it depends on how water runs down your door. Prevention is always better than cure! If you are going with the foam baffles/pod, do not leave them sealed as this will rob all your midbass. You can use a knife to cut the underside essentially leaving a hood for your woofer.
While good car audio manufacturers design with use in mind for car doors which is a moisture rich environment, they can never mitigate against water running on the woofer parts itself.
If you would like to give your woofer the longest chance of living I would say yes, go for it.