Foundation

I was in a house with a garage underneath that you could access from either the front or the back of the home so it was like the house had an underground drive-thru.  In the garage, there were two black cats the size of martens who were fighting. It made me think of how Merlin saw dragons fighting under the foundation of King Arthur's castle in progress. (I read this in Mary Stewart's Merlin Trilogy) The fighting causes the structure to constantly fall down.  I worried about the house until I woke up.  

I dreampt I invented a filter for car windows that worked as a photo filter.  The filter used a search tool to look for images from the same year the car was made.  If you sat in the car the filter would put a glamor on you to update your appearance to a particular year so your clothes, hair, and makeup were historically accurate. For some reason, I didn't sell the technology but I just applied it to more and more vintage cars that I kept in my driveway.