It has nothing to do with "Getting rid of the Contour" or "Getting into a new car".
It's John's circumstances:
1. John, Jr. is on the way
2. his SVT is almost paid off
3. his SVT has low miles
4. his SVT is not a daily driver
He'll be done paying the SVT off soon - it doesn't make sense to start car payments all over again with kid on the way!