Go give them pets. I'm sure if the owner knows they're chill enough to just sit in the back of his truck faithfully guarding his valuable pack of marlboros and the 10 year old kenwood up front he knows they're chill enough for people to come pet them.
Speaks strides of the owner.
Go pet them and if the owner sees you tell him you couldn't help yourself and you love dogs. He might become a good bro and you get the bonus of getting to play with his dogs.