Yes bhai, I am talking about Jamshoro Barrage. The car used to wobble heavily while driving on it. The other road I felt wobbling while driving Wagon R was that from Poonam Petrol Pump to Qasim Chowk and back. I have been driving since 2007, the other cars I drove were Potohar Jeep, Charade, Mehran, Cuore, JDM Kei, Wagon R, and now Corolla, but earnestly speaking, never felt this issue of wobbling except in Wagon R. I can't term it an issue of misalignment/imbalance because in that case, the car vibrates, but doesn't wobble (moving in the direction of wind).
Comparing Wagon R with Passenger buses would be unjustified as these buses are many many times heavier than Wagon R, and as such are not affected by material wobbling issues, Wagon R being many times lighter in weight is therefore more prone to the risk of wobbling.
I have gone to Hyderabad-Karachi super highway on my father's official APV (Which is the elder brother of Wagon R :P), and never felt any wobbling issues with it. Yes, I do agree with you that little bit wobbling on tall body designs is normal, but at least I felt it a serious threat to my family's safety