I am staying at the BW Lake Buena Vista at DD in September. I was told by the BW via email, in regard to the same question, that DD hotels do NOT have parking privilages. Length of stay passes can be purchased, and early entry (now a mute point) were part of the DD package, but not parking.
The busses, from what I've learned in extensive research, are a little slow, as they serve all Hotel Plaza properties and stop at all parks. However, another alternative is to walk to DD (should be ten minutes or so from the Courtyard) and take WDW transportation from DD to the parks, supposedly a much quicker option.
Pat