Tiguan :: 2009 SE VW Shakes While Driving

I have a 2009 Tiguan SE 4Motion with a little over 82K miles on it. Hard to pin point exactly but somewhere around 65 - 68K the vehicle started shaking, noticeably but not ridiculously while driving at a decent speed, 50 mph seems to be the speed where it's most notable. I took it to the dealer and they diagnosed it as the tires needed to be replaced. I had the tires replaced a few K later but the shake was the same. I took it back to the dealer who did the basic balance troubleshooting but they were unable to find anything. I pressed them and they did some additional troubleshooting but then I felt like I was wasting my time with that dealer because they started looking at the floor and talking nonsense about road conditions.

I feel the shaking regardless of road surface or speed, noticeable but not violent, 50mph and steady seems to be most noticeable. I feel that it is transmission/drive train related because everything else it could be has been checked or changed but I could be wrong. I feels like it's directly under the vehicle, I have sat in different seats while someone else drove and it doesn't seem to be more noticeable on one side or another. When on the highway going a steady speed on it will increase and decrease seemingly randomly. It hasn't really gotten any worse over the past 15K miles or I would have brought it to a different dealer, but it really bothers me, especially since my Tiguan was so smooth when I bought it.