SF - I enjoyed reading your report and I'm happy to read that you didn't encounter any problems driving to Paracas and back. Seems that you were well prepared for the trip. Driving in Peru is certainly different that driving in the U.S. and unless you have a good map it is easy to get lost or to take the wrong exit from the highway. On the other hand, I'd take driving in Peru over being stuck in traffic on the 101 at rush hour! (I've been in the Bay area at least twice a month so far this year.)
Good thing you didn't have any problems with the police roadblocks. Sometimes they try to find something wrong to force you to 'facilitate' your way out of an imaginary violation.