C.K.
You don't say how long this has been going on, but "blips" in the nap schedule are totally normal, esp. when your baby is teething or achieving a milestone. (Is he starting to crawl? Sit up on his own?)
I would stop driving around and nursing him to sleep. You are setting yourself up for a high maintenance baby. Those habits will be hard to break another 6 months from now.
I don't know how you feel about "crying it out", but at that age, we let our son cry for 10-15 minutes. If it was clear he wasn't going to settle down for a nap, then we got him up.