You've done a very good job in Photo Shop making this look older and the sepia helps in that regard a lot. I for one probably wouldn't have noticed that other car in the reflection or if I had, I wouldn't have been able to tell you what it was. But I suppose that the type of person that would be interested in looking at a pic like this would be able to spot it, if it was seen. Six of one, half a dozen of the other. I think you did a fine job. :)
"The artist is a receptacle for emotions that come from all over the place; from the sky, from the earth, from a scrap of paper, from a passing shape, from a spider’s web." Pablo Picasso