I think you are the first classic film enthusiast I've heard say that she actually likes the commercial! I'm glad someone likes it. I am not opposed to using classic film stars in commercials, but I don't think they did that great a job with this one.
I liked it because they weren't afraid to use classic stars to introduce a new product. They could have used any dancers to promote the back seat space, stars that might appeal to younger audiences better than Gene Kelly and Donald O'Connor, but they chose these classic dancers instead. For that alone, I applaud their efforts