Paul and Paula take a cross country trip

[JeanLucCheri]

Read this story a while back and I loved it, but I can't find it anymore. Guy named Paul is driving a Cadillac cross-country as a favor, and he picks up a girl named Paula. (A riff on the old song, 'Hey Paula')
It's a slow seduction as they travel across the country, and end up having sex in the car on a Florida beach.

Thanks in advance to anyone who can point me to it.