Hi there, if you only have a week, you don´t want to spend half of your week on the road dodging real speed demons. I have done plenty of cross country driving in Spain, and I am always stunned by land missiles that seem to appear on my tail as if they have just dropped out of "warp drive". Consider the night train for sure, or better yet, Iberia Airlines is economical in-country (I am told). The hike from Barcelona to Madrid is substantial and not peppered with the most spectacular scenery - unless you are stopping in Zaragosa (well worth it), you would do well to save time for exploring your target cities where you will want to linger for just one more festive beverage at some clever locale. - ¡Happy Holiday!