The buses run from 4 a.m. to midnight 'at regular intervals'. [=there is the same amount of time between buses]
It's nothing special, just a 'regular' [='basic'] stereo. = It's just a 'regular old' stereo.
He is one of the store's 'regular customers'. [=customers who shop at the store frequently]
(..) and he just shows up. They send me outside and the two of them talk. That's it. So this is, like, a regular thing? How close were you to him? Close. Closer than you and me right now. Did he speak to you? (..)2011 TvShow: Breaking Bad Title: Problem Dog Season: 4 Episode 7