The
DIS site also has a park hours/parades/show schedule page.
For Fantasmic, if you have a wheelchair or
ecv, the parking spots for those are in the back row. The whole back row of the seating area is divided off for wheelchair/ecv parking and one seat to sit next to the person with a wheelchair. Other members of your party (or people with special needs who do not have a wheelchair/ecv) sit in the row directly in front of the last row. You do get a good view of the "action". There are a few wheelchair seats in the front row, but there are disadvantages to those. You have to get there early since there are only a few and if the wind is blowing from the water toward the seating, you will get quite wet. DH and I sat in the second row from the front when we were at WDW in July. We prefer the back since you get to see more of the whole stage.
For Illuminations, there are some specific wheelchair viewing areas that are marked on the park maps. Depending on how many people with disabiltities choose to use them on any given night, they might be very crowded (wheelchair-to-wheelchair) and you might have to park yourself there as much as an hour and 1/2 before the show. DD is not much into waiting in crowded conditions, so we prefer to find our own spot. They announce that there are plenty of good viewing spots around the WS Laggon, and they are not exagerrating.
During the late afternoon, look for the barges and large pipes sticking up from the water in the WS Lagoon. A lot of the action takes place on the water. If you have a clear view of those from where you wait, you will have a clear view of the show. There is a fence along the WS Lagoon, so if you are waiting against the fence, no one will be in front of you. Interestingly, the only time we have had a really obstructed view of Illuminations was once when we did use the wheelchair viewing area. DD ended up behind a tree and really couldn't see anything once the show began.