Aw, I feel for you. Let's look at it positively and say he does feel the chemistry but he feels awkward as well. Even if you are in your thirties, each of you certainly has some fear of rejection. Maybe he didn't think you kissed him back during the new year's kiss and was just surprised when you kissed him when getting out of the car?
For him to continuously contact you, it seems he must think something of you. As far as not calling, emailing may feel "safer" for him, maybe this way he won't feel rejection as easily as if you wouldn't answer the phone when he called. I wouldn't give up and would certainly try to give him a chance. Good luck!