The DLH has three towers. Two of them, the Marina and the Bonita do have some parking lot views. However, the parking lot views in the Marina are better since you can also see a slice of the park (some rooms more than others depending on where you are located on that side) and can see the fireworks from that side as well. The Bonita is really the only one where you run the risk of a total, non interesting, nothing but a parking lot view. I would call them back and ask to have it noted on your reservation you would like a view that is not the parking lot. Just know that its a request and may not be granted. I have had the Bonita parking lot view and while it wasn't the best we didn't spend much time looking out the window. That was my first trip, pre Disboard days when I didn't know about all these things. Now when I go standard I just ask to be in any tower with a non lot view and in the last four stays I have gotten that just fine (always a standard room). However, even when I have had a nicer view, I only glanced at it first thing in the morning before we got started on our day. The DLH is a great property with lots of lovely landscaping to explore and enjoy, great dining options, nice large rooms with lovely Disney touches and lots more. You will love it!
Oh and again, I would call now but I would also call the morning you check in (after 11:00 when others have checked out and they will start assignig the new check in's rooms) if possible since that is when they will be assigning the rooms. Just a friendly little reminder call the day of never hurts. I have done that even in the airport waiting for my flight just to increase my chances. Good luck!