Didn't you mention you were in a high parvo area? I wouldn't take chances until that third set around 16 weeks.
I personally do take puppies out and about right from the start in the car and in general areas. I simply carry them in public places so they get used to the sounds and sights, once the final shots are done I remove all limitations.
Exactly what I do. I even had this little pouch thing I'd carry my recent puppy around in when he was small enough. He would hear and see everything without actually touching the ground and exposing him to things.