To me it sounds like a investigative stop. Meaning, by asking you first about drugs and or alcohol somthing else was on his mind. The speeding/lane change sounded secondary.
*Not a good idea to ask to see radar. Asking violates rule #1. "POP" Pissing Off Police. Nobody, especially Police like being challenged, like it or not.
Nothing like harrassing the public after some good donuts
