I recently ran the self-cleaning cycle on my oven. It got the inside of the oven perfectly clean, except for the glass on the door, which was still covered with brown and black spots and streaks. I found this tip online to clean the door and it worked great!
1. Combine 1/4 cup of baking soda and 1 Tbsp. of water to create a thick paste.
2. Cover the oven door with the paste (I used my pastry brush to spread it over the glass.)
3. Leave it alone for 30 minutes.
4. Wash off the paste - using a sponge with a textured side for scrubbing will ensure that everything is removed.