Me thinks the tires were balanced with the flat spot in them already so when they heat up, it does not go away. (and to the one poster, the flat spot we speak of is not braking related, but cold weather sitting for a while related).
Lbj, I would drive the car for 20-30 mins in the highway at speed to warm them up, and then have the tires road force balanced at the dealers cost. If that does not solve the issue, have the dealer replace the tire.
2013 X3 28i, AW, Chestnut, Sienna, ZAP, ZCV, ZCW, ZDH, ZPP, DHP, rear view, park distance, cargo net (Wife's)
2010 Porsche Boxster S (Mine)