The officer doesn't have to Mirandize him at all, unless he begins a custodial interrogation. He ought to, sure, once things are secure. One would hate for the suspect to confess that he was the weedwacker serial killer on the way to the jail, and then have that confession overturned because the officer had not receited the mantra handed down by Chief Justice Warren.
Didn’t the USSC rule, about ten years ago, that a guy that blurts out a confession while he’s not being questioned (sitting in the back of a cruiser) has no right to a Miranda warning?
The whole Miranda thing is a joke anyway.
If you don’t already know your rights, you don’t have any.