Thank you for the kind reply bro. The reason why I am concerned about front passenger seat vibration is the fact that I haven't observed this issue in 10th generation GLI, being driven at high speeds on stock tyres. Mine being 11th generation, shouldn't have this issue. I am looking for all possible causes of this problem, from respected members here. Tire alignment and balancing being the most common cause. I will get it done on my first free inspection due in January 2016. My Altis 1.6 has merely clocked 297 KMs, so even after balancing/alignment, if the issue doesn't get resolved, I would better think of changing stock tires, as they would fetch more money if traded off with less than 500 KMs of usage.